As filed with the U.S. Securities and Exchange Commission on June 11, 2026.

Registration No. 333-295869

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Amendment No. 1 to
FORM S-4

REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

D. Boral ARC Merger Corporation*

(Exact name of registrant as specified in its charter)

D. Boral ARC Acquisition I Corp. 

10 East 53rd Street, Suite 3001

New York, NY 10022
Tel. No. (332) 266-7344

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

David Boral
10 East 53rd Street, Suite 3001

New York, NY 10022
Tel. No. (332) 266-7344

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after this registration statement becomes effective and all other conditions to the transactions contemplated by the Business Combination Agreement described in the included proxy statement/prospectus have been satisfied or waived.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box. ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer) ☐

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer) ☐

The registrant and co-registrant hereby amend this registration statement on such date or dates as may be necessary to delay its effective date until the registrant and co-registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act or until the registration statement shall become effective on such date as the SEC, acting pursuant to said Section 8(a), may determine.

TABLE OF CO-REGISTRANT

820 Gessner Road, Suite 332

Houston, TX 77024

Exascale Labs Inc.

Attn: Hoansoo Lee

820 Gessner Road, Suite 332

Houston, TX 77024

The information in this proxy statement/prospectus is not complete and may be changed. D. Boral ARC Merger Corporation may not issue the securities offered by this proxy statement/prospectus until the registration statement filed with the Securities and Exchange Commission, of which this proxy statement/prospectus is a part, is declared effective. This proxy statement/prospectus does not constitute an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale of these securities is not permitted.

PRELIMINARY — SUBJECT TO COMPLETION, DATED JUNE 11, 2026

PROXY STATEMENT FOR EXTRAORDINARY GENERAL MEETING OF

D. BORAL ARC ACQUISITION I CORP.

(a British Virgin Islands business company)

PROSPECTUS

FOR UP TO 60,456,000 SHARES OF CLASS A ORDINARY COMMON STOCK,

30,744,000 SHARES OF CLASS B SUPER COMMON STOCK, AND

14,100,000 WARRANTS TO PURCHASE SHARES OF CLASS A ORDINARY COMMON STOCK

(For Issuance)

OF

D. BORAL ARC MERGER CORPORATION

(to be renamed “Exascale Labs Holdings Inc.” in connection with the Business Combination described herein)

On January 11, 2026, D. Boral ARC Acquisition I Corp., a British Virgin Islands business company (“BCAR” or the “Parent”), entered into that certain Agreement and Plan of Merger (as it may be amended, supplemented or otherwise modified from time to time, the “Business Combination Agreement”), by and among BCAR, D. Boral ARC Merger Corporation, a Delaware corporation and a direct, wholly owned subsidiary of BCAR (“PubCo”), D. Boral Arc Merger Sub Inc., a Delaware corporation and a direct, wholly owned subsidiary of BCAR (“Merger Sub”), and Exascale Labs Inc., a Delaware corporation (the “Company” or “Exascale”). Capitalized terms used but not defined herein shall have the meaning given to them in the Business Combination Agreement. A copy of the Business Combination Agreement is attached to this proxy statement/prospectus as Annex A.

Exascale is a next-generation artificial intelligence (“AI”) infrastructure provider operating an asset-light, software-defined graphics processing unit (“GPU”) compute platform and related AI infrastructure solutions. Exascale’s core business includes GPU-as-a-Service (“GaaS”), through which it provides reserved and on-demand access to high-performance GPU compute capacity sourced from third-party data centers globally, as well as GPU cluster management and optimization services for AI data center (“AIDC”) operators. In addition, Exascale has developed certain modular data center, high-density liquid cooling, high-voltage direct current (“HVDC”) power and energy storage solutions that are designed to address deployment bottlenecks in AI infrastructure and that Exascale believes are ready for commercial engagement, although these capabilities have not yet generated revenue as of the date of this proxy statement/prospectus. The platform is purpose-built for large-scale AI workloads, including large language model (“LLM”) training, fine-tuning, and high-concurrency inference. Additional information about Exascale is set forth in the section titled “Information about Exascale” in this proxy statement/prospectus.

The Business Combination Agreement provides that, among other things and upon the terms and subject to the conditions thereof, the following transactions will occur (together with the other agreements and transactions contemplated by the Business Combination Agreement, the “Business Combination”):

The BCAR Board has determined that the Business Combination and the transactions contemplated thereby are fair to and in the best interests of BCAR and its shareholders because they believe that Exascale is a company with strong revenue growth potential. In reaching its decision with respect to the Business Combination and the transactions contemplated thereby, the BCAR Board reviewed various industry and financial data and the due diligence and evaluation materials provided by Exascale, demonstrating that Exascale has a business plan dedicated to both near term cash flow as well as long term growth. See “The Business Combination Proposal — BCAR Board of Directors’ Reasons for the Approval of the Business Combination” on page 130.

Consideration and Structure

Under the Business Combination Agreement, the Merger Consideration is 50,000,000 shares of PubCo Common Stock to be issued at the closing of the Business Combination. Holders of shares of Exascale Class A common stock and Exascale securities convertible or exchangeable for shares of Exascale Class A common stock (including the Exascale Safeholders, the Base Camp Investor and the Exascale Equity Incentive Recipients) will receive shares of PubCo Class A Ordinary Common Stock for such Exascale securities, and holders of Exascale Class B common stock will receive shares of PubCo Class B Super Common Stock for such Exascale securities. Completion of the Business Combination is subject to the satisfaction or waiver, where permissible, of various conditions to closing.

BCAR’s Units, Class A Ordinary Shares and Public Warrants are currently traded on the Global Market tier of the Nasdaq Stock Market LLC under the symbols “BCARU,” “BCAR” and “BCARW,” respectively. BCAR has applied to have the PubCo Class A Ordinary Common Stock (as defined below) and the PubCo Warrants (as defined below) listed on Nasdaq under the ticker symbols “XLAB” and “XLABW,” respectively. It is a condition precedent to the consummation of the Business Combination that BCAR receive confirmation from Nasdaq (or another nationally recognized securities exchange in the United States as may be agreed by BCAR and Exascale) that the securities have been conditionally approved for listing on such exchange, but there can be no assurance such listing conditions will be met or that BCAR will obtain such confirmation from such exchange.

The following summarizes the pro forma ownership of PubCo’s Class A common stock, par value $0.0001 per share and having one (1) vote per share (“PubCo Class A Ordinary Common Stock”), and PubCo’s Class B common stock, par value $0.0001 per share and having twenty (20) votes per share (“PubCo Class B Super Common Stock”), immediately following the Business Combination across a range of varying redemption scenarios.

Stockholders will experience additional dilution to the extent PubCo issues additional shares of PubCo Common Stock in connection with any Minimum Cash Financing and/or after the closing of the Business Combination. The table above excludes any shares that will be issuable upon the exercise or settlement of: (i) the 100,000 Private Placement Warrants, and (ii) the 14,000,000 Public Warrants.

Dilution

The following table illustrates varying ownership levels in PubCo immediately following the consummation of the Business Combination based on the varying levels of redemptions by the Public Shareholders, on a fully diluted basis, showing full exercise and conversion of all securities, including the Public Warrants and Private Placement Warrants.

Although the PubCo Class A Ordinary Common Stock and PubCo Class B Super Common Stock have identical economic rights, each holder of PubCo Class A Common Stock shall be entitled to one (1) vote for each share of PubCo Class A Ordinary Common Stock held and twenty (20) votes for each PubCo share of PubCo Class B Super Common Stock held.

For more information, please see the sections entitled “Questions and Answers for Shareholders of BCAR—What will Exascale Securityholders receive in connection with the Business Combination?” Proposal No. 1—The Business Combination Proposal—The Business Combination Agreement—Consideration,” “Unaudited Pro Forma Condensed Combined Financial Information—Description of the Transactions,” “Unaudited Pro Forma Condensed Combined Financial Information.”

All of the relative percentages above are for illustrative purposes only and are based upon certain assumptions as described in the section entitled “Unaudited Condensed Combined Pro Forma Financial Information”. For more information, including the ownership percentages giving effect to certain dilutive securities, see the section entitled “The Business Combination Proposal—Ownership of PubCo after the Closing”.

Conflicts of interest

Certain of BCAR’s directors and executive officers may be deemed to have interests in the transactions contemplated by the Business Combination Agreement that are different from, or in addition to, those of BCAR’s shareholders generally. These interests may present these individuals with certain potential conflicts of interest. BCAR’s independent directors reviewed and considered these interests during their evaluation and negotiation of the Business Combination and in unanimously approving, as members of the BCAR Board, the Business Combination Agreement and the transactions contemplated therein, including the Business Combination. The BCAR Board concluded that the potential benefits that it expected BCAR and its shareholders to achieve as a result of the Business Combination outweighed the potentially negative factors associated with the Business Combination. When you consider the recommendation of the BCAR Board in favor of approval of the Business Combination, you should keep in mind that BCAR’s directors and officers have interests in the Business Combination that are different from, or in addition to, your interests as a shareholder, including the following:

The foregoing interests may influence the officers and directors of BCAR to support or approve the Business Combination. As such, the Sponsor and BCAR’s officers and directors may be incentivized to complete an acquisition of a less favorable target company or on terms less favorable to BCAR’s shareholders rather than liquidate. In considering the recommendations of the BCAR Board to vote for the proposals, BCAR’s shareholders should consider these interests.

The following table sets forth the payments to be received by BCAR’s promoters and the Sponsor and its affiliates from BCAR prior to or in connection with the completion of the Business Combination and the securities issued and to be issued by BCAR to the Sponsor or its affiliates. Since the Insiders, and any other holders of BCAR’s Founder Shares may lose their entire investment in BCAR if the Business Combination is not completed, a conflict of interest may arise in determining whether Exascale is appropriate for BCAR’s initial business combination.

For more information, please see Section – “Directors, Officers, Executive Compensation and Corporate Governance of BCAR Prior to the Business Combination – Conflicts of interest” on page 208.

Pursuant to the Business Combination Agreement, BCAR agreed to cause PubCo to receive an amount of at least $5,000,000 in any combination of cash, cash in the trust account, a private investment in public equity (“PIPE”), an equity line of credit, or third-party financing, net of any outstanding checks, wire transfers, or similar items not yet cleared, and net of any cash distributions or transfers made in connection with or as a result of the Business Combination (the “Minimum Cash Financing”). It is a condition precedent to Closing that PubCo receive the Minimum Cash Financing. If the Minimum Cash Financing is not met, and such condition is not waived by Exascale under the terms of the Business Combination Agreement, the proposed Business Combination will not be consummated. In the event that the Business Combination will not be consummated, all Public Shares submitted for redemption will be returned to the holders thereof, and BCAR may instead search for an alternate business combination or liquidate BCAR. As of the date hereof, neither BCAR nor Exascale has secured financing for the Minimum Cash Financing. The management teams of BCAR and Exascale are continuing to analyze the available financing options based on cost, amount available under any such facility and future effects that any financing would have on the capitalization of PubCo. BCAR, the Sponsor, Exascale and their affiliates will have no prior relationships with any of the potential financing sources that will be considered in connection with the Business Combination. Upon entry into a financing arrangement for the Business Combination, including any Minimum Cash Financing, BCAR will disclose such arrangement (including the potential dilution) in accordance with the rules of the SEC.

At any time at or prior to the Extraordinary General Meeting, during a period when they are not then aware of any material nonpublic information regarding BCAR or its securities, the Sponsor, BCAR’s officers, BCAR’s directors and/or their affiliates, in compliance with the tender offer rules and other Exchange Act limitations, including Rule 14e-5 thereunder, may purchase Public Shares from institutional and other investors, execute agreements to purchase shares from such investors in the future, or they may enter into transactions, including non-redemption agreements, with such investors and others to provide them with incentives to acquire shares of BCAR and/or not to redeem (or to validly rescind any redemption requests). The Sponsor, BCAR’s officers, BCAR’s directors and/or their affiliates anticipate that they may identify such unaffiliated third-party shareholders with whom the Sponsor, BCAR’s officers, BCAR’s directors or their affiliates may pursue privately negotiated transactions by either the shareholders contacting BCAR directly or by BCAR’s receipt of redemption requests submitted by shareholders following BCAR’s mailing of tender offer or proxy materials in connection with the Business Combination. To the extent that the Sponsor, BCAR’s officers, BCAR’s directors, BCAR’s advisors or their affiliates enter into a private transaction with an unaffiliated third party, they would identify and contact only potential selling or redeeming shareholders who have expressed their election to redeem their shares for a pro rata share of the trust account, whether or not such shareholder has already submitted a proxy with respect to the Business Combination but only if such shares have not already been voted at the Extraordinary General Meeting related to the Business Combination. The Sponsor, BCAR’s officers, BCAR’s directors, BCAR’s advisors or their affiliates will select which shareholders to purchase shares from based on the negotiated price and number of shares and any other factors that they may deem relevant, and will be restricted from purchasing shares if such purchases do not comply with Regulation M under the Exchange Act and the other federal securities laws. Any such privately negotiated transactions may be effected at purchase prices that are no greater than the per share pro rata portion of the trust account. Such privately negotiated transactions may include a contractual acknowledgement that such unaffiliated third-party shareholder, although still the record or beneficial holder of BCAR’s shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights. In the event that the Sponsor, BCAR’s officers, BCAR’s directors and/or their affiliates purchase shares in privately negotiated transactions from unaffiliated third-party shareholders who have already elected to exercise their redemption rights, such selling shareholders would be required to revoke their prior elections to redeem their Public Shares. The purpose of such share purchases and other transactions would be to limit the number of Public Shares electing to be redeemed.

In accordance with the SEC’s Compliance and Disclosure Interpretation 166.01, any Public Shares purchased by the Sponsor, BCAR’s officers, BCAR’s directors and/or their affiliates would not be voted in favor of approving the Business Combination.

Except as disclosed in this proxy statement/prospectus, BCAR has not entered into any privately negotiated transactions with respect to its shares as of the date hereof. If they engage in such privately negotiated transactions, the Sponsor, BCAR’s officers, BCAR’s directors and/or their affiliates will be restricted from making any such purchases when they are in possession of any material non-public information not disclosed to the seller or if such purchases are prohibited by Regulation M under the Exchange Act.

The Sponsor, BCAR’s officers, BCAR’s directors and/or their affiliates will be restricted from making purchases of shares if the purchases would violate Section 9(a)(2) of, or Rule 10b-5 under, the Exchange Act. BCAR expects any such purchases would be reported by such person pursuant to Section 13 and Section 16 of the Exchange Act to the extent such purchasers are subject to such reporting requirements. Additionally, in the event the Sponsor, BCAR’s directors, BCAR’s officers, BCAR’s advisors, or their affiliates were to purchase shares from Public Shareholders, or if any third party investors are incentivized to acquire Public Shares by the Sponsor, BCAR’s directors, BCAR’s officers, or their affiliates, such purchases would be structured in compliance with the requirements of Rule 14e-5 under the Exchange Act including, in pertinent part, through adherence to the following:

None of the funds in the trust account will be used to purchase Public Shares in such transactions.

Investing in PubCo’s securities involves a high degree of risk. We encourage you to read this proxy statement/prospectus carefully. In particular, you should review the matters discussed under the section entitled “Risk Factors.”

BCAR will hold an Extraordinary General Meeting of its shareholders (the “Extraordinary General Meeting”) to consider matters relating to the Business Combination at 10:00 A.M., Eastern Time, on [_], 2026. The Extraordinary General Meeting will be a virtual meeting conducted via live webcast. For the purposes of British Virgin Islands law and the Current Charter, the physical location of the meeting will be at the offices of Loeb & Loeb LLP, 345 Park Avenue, New York, NY 10154 on [_], 2026, at 10:00 A.M. Eastern Time and virtually using the following dial-in information: Telephone number: __________________ Participant Passcode: __________________.

As of the date of this proxy statement/prospectus, there was approximately $[_] in BCAR’s trust account. On [_], 2026, the last sale price of BCAR Class A Ordinary Shares was $[_] per share.

Pursuant to BCAR’s existing amended and restated memorandum and articles of association (the “Current Charter”), BCAR is providing its Public Shareholders with the opportunity to redeem all or a portion of their Public Shares at a per-share price, payable in cash, equal to the aggregate amount then on deposit in BCAR’s trust account as of two business days prior to the consummation of the Business Combination, including interest, less taxes payable, divided by the number of then outstanding Public Shares that were sold as part of the BCAR Units in the IPO, subject to the limitations described herein. BCAR estimates that the per-share price at which Public Shares may be redeemed from cash held in the trust account will be approximately $[_] at the time of the Extraordinary General Meeting. BCAR’s Public Shareholders may elect to redeem their shares even if they vote for the Business Combination Proposal or do not vote at all. BCAR has no specified maximum redemption threshold under BCAR’s Current Charter. Holders of outstanding BCAR Warrants do not have redemption rights in connection with the Business Combination. Notwithstanding the foregoing redemption rights, a public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Exchange Act), will be restricted from redeeming its shares with respect to more than an aggregate of 15% of the shares sold in the IPO without BCAR’s prior consent. However, BCAR will not restrict shareholders’ ability to vote all their shares (including all shares held by those shareholders that hold more than 15% of the shares sold in the IPO) for or against the Business Combination.

On [_], 2026, the record date for the Extraordinary General Meeting (the “Record Date”), the last sale price of BCAR Class A Ordinary Share was $[_].

If you have any questions or need assistance voting your BCAR shares, please contact Advantage Proxy, Inc., BCAR’s proxy solicitor, by email at karen@advantageproxy.com. Individuals may also call Advantage Proxy toll free at 877-870-8565; banks and brokers can call 206-870-8565. The notice of the Extraordinary General Meeting and the proxy statement/prospectus relating to the Business Combination will be available at www.sec.gov or https://www.cstproxy.com/[_].

This document is (i) a prospectus related to the issuance by PubCo of PubCo Common Stock and PubCo Warrants in the Business Combination and (ii) a proxy statement for BCAR to use in soliciting proxies for the Extraordinary General Meeting. The Insiders, who own approximately 32.0% of BCAR’s outstanding ordinary shares as of the Record Date, have agreed to vote all shares they own in favor of the Business Combination Proposal, and intend to vote for each of the other proposals as well, although there is no agreement in place with respect to voting on those proposals.

This proxy statement/prospectus provides shareholders of BCAR with detailed information about the Business Combination and other matters to be considered at the Extraordinary General Meeting of BCAR. We encourage you to read this entire document, including the Annexes and other documents referred to herein, carefully and in their entirety. You should also carefully consider the risk factors described under the heading “Risk Factors.”

BCAR’s board of directors unanimously recommends that BCAR shareholders vote “FOR” approval of each of the proposals.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE TRANSACTIONS DESCRIBED IN THIS PROXY STATEMENT/PROSPECTUS, PASSED UPON THE MERITS OR FAIRNESS OF THE PROPOSED TRANSACTIONS OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE DISCLOSURE IN THIS PROXY STATEMENT/PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY CONSTITUTES A CRIMINAL OFFENSE.

IF YOU RETURN YOUR PROXY CARD WITHOUT AN INDICATION OF HOW YOU WISH TO VOTE, YOUR SHARES WILL BE VOTED IN FAVOR OF EACH OF THE PROPOSALS.

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST ELECT TO HAVE BCAR REDEEM YOUR SHARES FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR SHARES TO BCAR’S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE VOTE AT THE EXTRAORDINARY GENERAL MEETING. YOU MAY TENDER YOUR SHARES BY EITHER DELIVERING YOUR SHARE CERTIFICATE TO THE TRANSFER AGENT OR BY DELIVERING YOUR SHARES ELECTRONICALLY USING THE DEPOSITORY TRUST COMPANY’S DWAC (DEPOSIT AND WITHDRAWAL AT CUSTODIAN) SYSTEM. IF THE BUSINESS COMBINATION IS NOT COMPLETED, THEN THESE SHARES WILL NOT BE REDEEMED FOR CASH. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS. PLEASE SEE THE SECTION TITLED “EXTRAORDINARY GENERAL MEETING OF BCAR SHAREHOLDERS - REDEMPTION RIGHTS” FOR MORE SPECIFIC INSTRUCTIONS.

D. BORAL ARC ACQUISITION I CORP.

British Virgin Islands Business Company

(Company Number WC-2172570)

10 East 53rd Street, Suite 3001, New York, NY 10022

(332) 266-7344

NOTICE OF EXTRAORDINARY GENERAL MEETING TO BE HELD ON [_], 2026

To the Shareholders of D. Boral ARC Acquisition I Corp.:

NOTICE IS HEREBY GIVEN that an Extraordinary General Meeting (the “Extraordinary General Meeting”) of D. Boral ARC Acquisition I Corp., a British Virgin Islands business company (“BCAR” or the “Parent”), will be held at the offices of Loeb & Loeb LLP, 345 Park Avenue, New York, NY 10154 on [_], 2026, at 10:00 A.M. Eastern Time and virtually using the following dial-in information: Telephone number: __________________ Participant Passcode: __________________.

Capitalized terms used but not defined herein shall have the meaning given to them in the accompanying proxy statement/prospectus.

For the purposes of British Virgin Islands law and the amended and restated memorandum and articles of association of BCAR (the “Current Charter”), the physical location of the Extraordinary General Meeting will be at the offices of Loeb & Loeb LLP, 345 Park Avenue, New York, NY 10154. You are cordially invited to attend the Extraordinary General Meeting, which will be held for the following purposes:

(1) Proposal No. 1 — The Business Combination Proposal — To consider and vote upon a proposal to approve by way of an ordinary resolution and adopt the Agreement and Plan of Merger, dated as of January 11, 2026 (the “Business Combination Agreement”), by and among BCAR, D. Boral ARC Merger Corporation, a Delaware corporation and a direct, wholly owned subsidiary of BCAR (“PubCo”), D. Boral Arc Merger Sub Inc., a Delaware corporation and a direct, wholly owned subsidiary of BCAR (“Merger Sub”), and Exascale Labs Inc., a Delaware corporation (the “Company” or “Exascale”), pursuant to which, among other things, following the closing of the Domestication Merger (as defined below), Merger Sub shall be merged with and into the Company, with the Company surviving the merger as a wholly-owned subsidiary of PubCo (the “Acquisition Merger”), and approve the Acquisition Merger and the other transactions contemplated by the Business Combination Agreement. The Acquisition Merger, together with the Domestication Merger and the other agreements and transactions contemplated by the Business Combination Agreement, are referred to herein as the “Business Combination.” We refer to this proposal as the “Business Combination Proposal.” A copy of the Business Combination Agreement is attached to the accompanying proxy statement/prospectus as Annex A.

(2) Proposal No. 2 — The Domestication Merger Proposal — To consider and vote upon a proposal to approve by way of an ordinary resolution and adopt the domestication of D. Boral ARC Acquisition I Corp., a British Virgin Islands business company (“BCAR” or the “Parent”) pursuant to the Business Combination Agreement, and subject to the conditions of the Business Combination Agreement, pursuant to which BCAR shall continue out of the British Virgin Islands and into the State of Delaware so as to re-domicile as and become a Delaware corporation by means of a merger (the “Domestication Merger”) of BCAR with and into PubCo, with PubCo as the surviving company pursuant to the Business Companies Act, (Revised Edition 2020) as amended, of the British Virgin Islands and Section 388 and other applicable provisions of the General Corporation Law of the State of Delaware (the “DGCL”). Upon the Domestication Merger, PubCo shall change its name to “Exascale Labs Holdings Inc.” We refer to this proposal as the “Domestication Merger Proposal.” A copy of the Business Combination Agreement is attached to the accompanying proxy statement/prospectus as Annex A.

(3) Proposal No. 3 — Organizational Documents Proposal — To consider and vote upon a proposal to approve by way of an ordinary resolution the proposed amended and restated certificate of incorporation (the “Proposed Charter”) and the proposed amended and restated bylaws (“Proposed Bylaws” and, together with the Proposed Charter, the “Proposed Organizational Documents”) of PubCo (a corporation incorporated in the State of Delaware), (the “Organizational Documents Proposal”). The forms of each of the Proposed Charter and the Proposed Bylaws are attached to the accompanying proxy statement/prospectus as Annex B-1 and Annex B-2, respectively.

(4) Proposal No. 4 — The Advisory Organizational Documents Proposals — To consider and vote upon the following six (6) separate proposals (collectively, the “Advisory Organizational Documents Proposals”) to approve on an advisory non-binding basis by way of an ordinary resolution the following material differences between the Current Charter and the Proposed Organizational Documents:

(A) Advisory Organizational Documents Proposal 4A (Authorized Shares) — authorize the amendment and redesignation of the authorized shares of BCAR from (a) 500,000,000 BCAR Class A Ordinary Shares, 50,000,000 BCAR Class B Ordinary Shares and 5,000,000 BCAR preference shares, in each case par value $0.0001 per share, to (b) 260,000,000 shares of PubCo Class A Ordinary Common Stock, 35,000,000 shares of PubCo Class B Super Common Stock, and 5,000,000 shares of PubCo Preferred Stock, in each case par value $0.0001 per share (“Advisory Organizational Documents Proposal 4A”).

(B) Advisory Organizational Documents Proposal 4B (Change in Voting Rights) — to change the voting rights of PubCo’s Common Stock such that, each PubCo Class A Ordinary Common Stock will be entitled to one (1) vote per PubCo Class A Ordinary Common Stock on all matters submitted to a vote of the stockholders of PubCo, and each PubCo Class B Super Common Stock will be entitled to twenty (20) votes per PubCo Class B Super Common Stock on all matters submitted to a vote of the stockholders of PubCo, and that the PubCo Class A Ordinary Common Stock and PubCo Class B Super Common Stock shall vote together on all matters except as explicitly required by the DGCL or as explicitly set forth in the Proposed Charter (“Advisory Organizational Documents Proposal 4B”).

(C) Advisory Organizational Documents Proposal 4C (Exclusive Forum Provision) — to authorize adopting Delaware as the exclusive forum for certain stockholder litigation and adopting the federal district courts of the United States as the exclusive forum for resolving complaints asserting a cause of action under the Securities Act of 1933, as amended (the “Securities Act”) (“Advisory Organizational Documents Proposal 4C”).

(D) Advisory Organizational Documents Proposal 4D (Required Vote to Amend Charter) — to approve provisions providing that the affirmative vote of at least 66⅔% of the voting power of all the then outstanding shares of capital stock of PubCo entitled to vote thereon, voting together as a single class, will be required to amend, alter, repeal or rescind any provision of Article FIFTH, Article SIXTH, Article SEVENTH, Article EIGHTH, Article NINTH, Article TENTH or Article ELEVENTH of the Proposed Charter (“Advisory Organizational Documents Proposal 4D”).

(E) Advisory Organizational Documents Proposal 4E (Removal of Directors) — to approve provisions permitting the removal of a director, but only for cause, and then by the affirmative vote of at least 66⅔% of the voting power of all the then outstanding shares entitled to vote generally in the election of directors, voting together as a single class (“Advisory Organizational Documents Proposal 4E”).

(F) Advisory Organizational Documents Proposal 4F (Name Change) — to approve the change of the name of PubCo to “Exascale Labs Holdings Inc.” (“Advisory Organizational Documents Proposal 4F”).

(5) Proposal No. 5 — Directors Proposal — A proposal to elect Hoansoo Lee, Wenying Jia, David Card, Shachar Kariv and Jaeyoung Shin as the directors of PubCo, with Hoansoo Lee to serve until the 2029 annual meeting and until his successor has been duly elected and qualified or until his earlier resignation, removal or death, with each of Wenying Jia and David Card to serve until the 2028 annual meeting and until their respective successors have been duly elected and qualified or until their earlier resignation, removal or death, and with each of Shachar Kariv and Jaeyoung Shin to serve until the 2027 annual meeting and until their respective successors have been duly elected and qualified or until their earlier resignation, removal or death (the “Directors Proposal”).

(6) Proposal No. 6 — The Equity Incentive Plan Proposal — To consider and vote upon a proposal to approve by an ordinary resolution the Equity Incentive Plan (the “Equity Incentive Plan Proposal”).

(7) Proposal No. 7 — The Nasdaq Proposal — To consider and vote upon a proposal to approve by an ordinary resolution, for purposes of complying with the applicable provisions of Nasdaq Stock Exchange Listing Rule 5635, the issuance of PubCo Common Stock and PubCo Warrants in connection with the Business Combination (the “Nasdaq proposal”).

(8) Proposal No. 8 — The Adjournment Proposal — To consider and vote upon a proposal to approve by way of an ordinary resolution the adjournment of the Extraordinary General Meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of one or more proposals at the Extraordinary General Meeting (the “Adjournment Proposal”).

Each of Proposal Nos. 1, 2, 3, 5, 6 and 7 is cross-conditioned on the approval of each other (the “Condition Precedent Proposals”). The Advisory Organizational Documents Proposal 4A-F and the Adjournment Proposal are not cross-conditioned upon the approval of any other proposal set forth in this proxy statement/prospectus. Notwithstanding the order of the resolutions on this notice to the Extraordinary General Meeting, the Adjournment Proposal may be presented first to the shareholders if, based on the tabulated vote collected at the time of the Extraordinary General Meeting, there are insufficient votes for, or otherwise in connection with, the approval of the Condition Precedent Proposals.

Pursuant to BCAR’s existing amended and restated memorandum and articles of association (the “Current Charter”), BCAR is providing its Public Shareholders with the opportunity to redeem all or a portion of their Public Shares at a per-share price, payable in cash, equal to the aggregate amount then on deposit in BCAR’s trust account as of two business days prior to the consummation of the Business Combination, including interest, less taxes payable, divided by the number of then outstanding Public Shares that were sold as part of the BCAR Units in the IPO, subject to the limitations described herein. BCAR estimates that the per-share price at which Public Shares may be redeemed from cash held in the trust account will be approximately $[_] at the time of the Extraordinary General Meeting. BCAR’s Public Shareholders may elect to redeem their shares even if they vote for the Business Combination Proposal or do not vote at all. BCAR has no specified maximum redemption threshold under BCAR’s Current Charter. Holders of outstanding BCAR Warrants do not have redemption rights in connection with the Business Combination. Notwithstanding the foregoing redemption rights, a public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Exchange Act), will be restricted from redeeming its shares with respect to more than an aggregate of 15% of the shares sold in the IPO without BCAR’s prior consent. However, BCAR will not restrict shareholders’ ability to vote all their shares (including all shares held by those shareholders that hold more than 15% of the shares sold in the IPO) for or against the Business Combination.

Only holders of record of BCAR Ordinary Shares at the close of business on [_], 2026 (the “Record Date”) are entitled to notice of and to vote at and to have their votes counted at the Extraordinary General Meeting and any adjournment of the Extraordinary General Meeting.

This proxy statement/prospectus and accompanying proxy card is being provided to BCAR’s shareholders in connection with the solicitation of proxies to be voted at the Extraordinary General Meeting and at any adjournment of the Extraordinary General Meeting. Whether or not you plan to attend the Extraordinary General Meeting, all of BCAR’s shareholders are urged to read this proxy statement/prospectus, including the Annexes and the documents referred to herein, carefully and in their entirety. You should also carefully consider the risk factors described under the heading “Risk Factors” beginning on page 54 of this proxy statement/prospectus.

After careful consideration, the board of directors of BCAR (the “BCAR Board”) has unanimously approved the Business Combination and unanimously recommends that shareholders vote “FOR” the adoption of the Business Combination Agreement, and approval of the transactions contemplated thereby, including the Business Combination Proposal, and “FOR” all other proposals presented to BCAR’s shareholders in this proxy statement/prospectus. When you consider the recommendation of these proposals by the BCAR Board, you should keep in mind that BCAR’s directors and officers have interests in the Business Combination that may conflict with your interests as a shareholder. Additionally, the Insiders have the right to vote an aggregate of 13,200,000 shares, or approximately 32.0% of the issued and outstanding BCAR Ordinary Shares. See “The Business Combination Proposal — Certain Interests of BCAR’s Directors and Officers and Others in the Business Combination” for a further discussion of these considerations.

The Business Combination Agreement is subject to the satisfaction or waiver of customary closing conditions, including, among others: (i) approval of the Business Combination and related agreements and transactions by the respective shareholders of BCAR and Exascale; and (ii) the effectiveness of the registration statement on Form S-4 filed by BCAR of which the accompanying proxy statement/prospectus forms a part.

The approval of each of the Business Combination Proposal, the Domestication Merger Proposal, the Organizational Documents Proposal, the Advisory Organizational Documents Proposals, the Directors Proposal, the Equity Incentive Plan Proposal, the Nasdaq Proposal and the Adjournment Proposal requires an ordinary resolution, being the affirmative vote of a simple majority of the votes cast by holders of BCAR Ordinary Shares, represented in person or by proxy and entitled to vote thereon at the Extraordinary General Meeting.

The Sponsor and each director and officer of BCAR (collectively, the “Insiders”) have agreed to, among other things, vote in favor of the Business Combination. The Sponsor together with each of the directors and officers of BCAR, own 13,200,000 BCAR Ordinary Shares, including (i) 12,000,000 Class B Ordinary Shares held by the Sponsor, (ii) 200,000 Class A Ordinary Shares underlying the Private Units, and (iii) 1,000,000 Representative Shares. As a result, as of the date of the accompanying proxy statement/prospectus, the Insiders own approximately 32.0% of the issued and outstanding BCAR Ordinary Shares.

Your vote is very important. Whether or not you plan to attend the Extraordinary General Meeting, please vote as soon as possible by following the instructions in the accompanying proxy statement/prospectus to make sure that your shares are represented at the Extraordinary General Meeting. If you hold your shares in “street name” through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that your shares are represented and voted at the Extraordinary General Meeting. The transactions contemplated by the Business Combination Agreement will be consummated only if the Condition Precedent Proposals are approved at the Extraordinary General Meeting.

If you sign, date and return your proxy card without indicating how you wish to vote, your proxy will be voted “FOR” each of the proposals presented at the Extraordinary General Meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the Extraordinary General Meeting in person, the effect will be that your shares will not be voted. An abstention or broker non-vote will be counted towards the quorum requirement but will not count as a vote cast at the Extraordinary General Meeting and otherwise will have no effect on a particular proposal because each proposal requires the affirmative vote of a particular number of votes cast and an abstention or broker non-vote is not a vote cast. If you are a shareholder of record and you attend the Extraordinary General Meeting and wish to vote in person, you may withdraw your proxy and vote in person.

Your attention is directed to the proxy statement/prospectus accompanying this notice (including the Annexes and other documents referred to therein) for a more complete description of the Business Combination and related transactions and each of the proposals. You are encouraged to read the accompanying proxy statement/prospectus carefully and in its entirety, including the Annexes and other documents referred to therein. If you have any questions or need assistance voting your BCAR Ordinary Shares, please contact Advantage Proxy, Inc., BCAR’s proxy solicitor, by email at Karen@advantageproxy.com. Individuals may also call Advantage Proxy toll free at 877-870-8565; banks and brokers can call 206-870-8565. This notice of Extraordinary General Meeting and the accompanying proxy statement/prospectus are available at www.sec.gov or https://www.cstproxy.com/[_].

Thank you for your participation. We look forward to your continued support.

By Order of the Board of Directors of D. Boral ARC Acquisition I Corp.

IF YOU RETURN YOUR PROXY CARD WITHOUT AN INDICATION OF HOW YOU WISH TO VOTE, YOUR SHARES WILL BE VOTED IN FAVOR OF EACH OF THE PROPOSALS.

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST ELECT TO HAVE BCAR REDEEM YOUR SHARES FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR SHARES TO BCAR’S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE VOTE AT THE EXTRAORDINARY GENERAL MEETING. YOU MAY TENDER YOUR SHARES BY EITHER DELIVERING YOUR SHARE CERTIFICATE TO THE TRANSFER AGENT OR BY DELIVERING YOUR SHARES ELECTRONICALLY USING THE DEPOSITORY TRUST COMPANY’S DWAC (DEPOSIT AND WITHDRAWAL AT CUSTODIAN) SYSTEM. IF THE BUSINESS COMBINATION IS NOT COMPLETED, THEN THESE SHARES WILL NOT BE REDEEMED FOR CASH. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS. PLEASE SEE THE SECTION TITLED “EXTRAORDINARY GENERAL MEETING OF BCAR SHAREHOLDERS - REDEMPTION RIGHTS” FOR MORE SPECIFIC INSTRUCTIONS.

The accompanying proxy statement/prospectus is dated [_], 2026 and is first being mailed to shareholders on or about [_], 2026.

TABLE OF CONTENTS

ABOUT THIS PROXY STATEMENT/PROSPECTUS

This proxy statement/prospectus, which forms part of a registration statement on Form S-4 filed with the Securities and Exchange Commission (the “SEC”) by BCAR, constitutes a prospectus of PubCo under Section 5 of the Securities Act, with respect to the PubCo Common Stock and PubCo Warrants to be issued to BCAR shareholders and warrant holders and Exascale securityholders if the Business Combination described herein is consummated. This document also constitutes a proxy statement of BCAR under Section 14(a) of the Exchange Act, and a notice of meeting with respect to the Extraordinary General Meeting of BCAR.

You should rely only on the information contained in this proxy statement/prospectus. BCAR and Exascale have not authorized anyone to provide you with information that is different from that contained in this proxy statement/prospectus. This proxy statement/prospectus is dated [_], 2026 and you should not assume that the information contained in this proxy statement/prospectus is accurate as of any date other than such date unless otherwise specifically provided herein.

This proxy statement/prospectus does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction.

This proxy statement/prospectus incorporates important business and financial information about BCAR that is not included or delivered herewith. If you would like to receive additional information or if you want additional copies of this document, agreements contained in the appendices or any other documents filed by BCAR with the SEC, such information is available without charge upon written or oral request to BCAR’s Chief Executive Officer at 10 East 53rd Street, Suite 3001, New York, NY 10022; or to Advantage Proxy LLC, our proxy solicitor, by email at karen@advantageproxy.com. Individuals may also call Advantage Proxy toll free at 877-870-8565; banks and brokers can call 206-870-8565.

In order for you to receive timely delivery of the documents in advance of the Extraordinary General Meeting of BCAR to be held on [_], 2026, you must request the information no later than five business days prior to the date of the Extraordinary General Meeting, by [_], 2026.

FREQUENTLY USED TERMS

Unless otherwise stated or unless the context otherwise requires, the terms “we,” “us,” “our,” “Parent,” and “BCAR” refer to D. Boral ARC Acquisition I Corp. (which prior to the Domestication Merger is a business company incorporated under the laws of the British Virgin Islands, and in connection with the Domestication Merger, will merge with and into D. Boral ARC Merger Corporation, a Delaware corporation). Following the Domestication Merger, D. Boral ARC Merger Corporation will be renamed “Exascale Labs Holdings Inc.” D. Boral ARC Merger Corporation is referred to in this document as PubCo.

In this document:

“Acquisition Merger” means the statutory merger of Merger Sub with and into Exascale pursuant to the terms of the Business Combination Agreement with Exascale continuing as the surviving entity and a wholly-owned subsidiary of PubCo.

“Adjournment Proposal” means the proposal to be considered at the Extraordinary General Meeting to adjourn the Extraordinary General Meeting to a later date or dates, if necessary to permit further solicitation and vote of proxies if it is determined by BCAR that more time is necessary or appropriate to approve one or more proposals at the Extraordinary General Meeting.

“Advantage Proxy” means Advantage Proxy, Inc., proxy solicitor to BCAR.

“Advisory Organizational Documents Proposals” means the proposals to be considered at the Extraordinary General Meeting to approve, on a non-binding advisory basis and as required by applicable SEC guidance, certain material differences between the Current Charter and the Proposed Organizational Documents.

“AI” means artificial intelligence.

“AIDC” means AI data center.

“Base Camp Investment Agreement” means the Base Camp Investment Agreement dated May 9, 2023, by and between Exascale and the Base Camp Investor.

“Base Camp Investor” means Outlier Ventures Operations Ltd.

“BCAR” means D. Boral ARC Acquisition I Corp.

“BCAR Board” means the board of directors of BCAR prior to the Closing.

“BCAR Class A Ordinary Shares” means, prior to the Domestication Merger, the Class A ordinary shares of BCAR, par value $0.0001 per share.

“BCAR Class B Ordinary Shares” means, prior to the Domestication Merger, the Class B ordinary shares of BCAR, par value $0.0001 per share.

“BCAR Ordinary Shares” means, collectively, the BCAR Class A Ordinary Shares and the BCAR Class B Ordinary Shares.

“BCAR Units” means the units of BCAR issued in the IPO, consisting of one Public Share and one-half of one BCAR Warrant.

“BCAR Warrant” means one whole redeemable warrant exercisable for one BCAR Class A Ordinary Share at an exercise price of $11.50 per share.

“Business Combination” means the transactions contemplated by the Business Combination Agreement and the other agreements contemplated therein.

“Business Combination Agreement” means the Agreement and Plan of Merger, dated as of January 11, 2026, by and among BCAR, Merger Sub, Exascale and D. Boral ARC Merger Corporation, and as it may be further amended and/or restated from time to time. A copy of the Business Combination Agreement is attached to this proxy statement/prospectus as Annex A.

“Business Combination Proposal” means the proposal to be considered at the Extraordinary General Meeting to approve the Business Combination.

“Business Day” means a day, other than a Saturday or Sunday, on which commercial banks in New York, NY are open for the general transaction of business.

“Current Charter” means BCAR’s Amended and Restated Memorandum and Articles of Association, as in effect on the date of this proxy statement/prospectus.

“Closing” means the closing of the Business Combination.

“Closing Date” means the date of the Closing.

“Code” means the U.S. Internal Revenue Code of 1986, as amended.

“Companies Act” refers to the Business Companies Act, (Revised Edition 2020) as amended, of the British Virgin Islands.

“Condition Precedent Proposals” mean the Business Combination Proposal, the Domestication Merger Proposal, the Organizational Documents Proposal, the Directors Proposal, the Nasdaq Proposal and the Equity Incentive Plan Proposal.

“DGCL” means the General Corporation Law of the State of Delaware.

“Directors Proposal” means the proposal to be considered at the Extraordinary General Meeting to elect the directors of PubCo.

“Domestication Merger” means the merger of BCAR with and into D. Boral ARC Merger Corporation, a Delaware corporation and wholly owned subsidiary of BCAR, upon which the separate existence of BCAR will cease and D. Boral ARC Merger Corporation will be the surviving corporation (such surviving company, “PubCo”) in accordance with the DGCL, the Companies Act, the Certificate of Merger, which is filed as Exhibit 3.5 to this proxy statement/prospectus (the “Certificate of Merger”), and the Current Charter.

“Domestication Merger Proposal” means the proposal to be considered at the Extraordinary General Meeting to approve the Domestication Merger.

“DWAC” means The Depository Trust Company’s deposit/withdrawal at custodian system.

“Effective Time” means the effective time of the Business Combination.

“Equity Incentive Plan” means the Exascale Labs Holdings Inc. 2026 Omnibus Equity Incentive Plan, which will become effective upon the Closing. A copy of the Equity Incentive Plan is attached to this proxy statement/prospectus as Annex C.

“Equity Incentive Plan Proposal” means the proposal to be considered at the Extraordinary General Meeting to approve the Equity Incentive Plan.

“Exascale” or the “Company” means Exascale Labs Inc., a Delaware corporation, and, if the context requires, Exascale Labs Inc. together with its subsidiaries.

“Exascale Board” means the board of directors of Exascale prior to the Closing.

“Exascale Common Stock” means the common stock, par value $0.01 per share, of Exascale.

“Exascale Equity Incentive Recipients” means, collectively, the persons entitled to receive shares of Exascale Class A Common Stock pursuant to outstanding share-based compensation awards.

“Exascale Safeholder” means holder of a SAFE.

“Exascale Securityholders” means, collectively, Exascale Stockholders, the Base Camp Investor, the Exascale Equity Incentive Recipients and Exascale Safeholders.

“Exascale Stockholder” means a holder of shares of Exascale Common Stock prior to the Closing.

“Exascale Support Agreement” means the support agreement, dated as of January 11, 2026, entered by and among BCAR, Exascale and certain stockholders of Exascale, as it may be amended and supplemented from time to time, pursuant to which such Exascale stockholders have agreed, among other things, to vote in favor of the adoption and approval of the Business Combination. A copy of the Exascale Support Agreement is attached to this proxy statement/prospectus as Annex E.

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended.

“Extraordinary General Meeting” means the extraordinary general meeting of BCAR’s shareholders, to be held virtually and in person at 10:00 A.M., Eastern Time on [_], 2026, at the offices of Loeb & Loeb LLP, 345 Park Avenue, New York, NY 10154, and any adjournments or postponements thereof.

“Founder Shares” means the 12,000,000 BCAR Class B Ordinary Shares acquired by the Sponsor prior to the IPO for the purchase price of $25,000.

“GaaS” means GPU-as-a-Service.

“GAAP” means U.S. generally accepted accounting principles.

“GPU” means graphics processing unit.

“HVDC” means high-voltage direct current.

“Initial Shareholders” means the holders of BCAR Class B Ordinary shares prior to the IPO.

“Insiders” means the Sponsor and each director and officer of BCAR.

“IPO” means BCAR’s initial public offering of 28,000,000 BCAR Units (each BCAR Unit consisting of one BCAR Class A Ordinary Share and one-half of one warrant to purchase one BCAR Class A Ordinary Share at a price of $11.50 per share) pursuant to registration statements on Form S-1 declared effective by the SEC on July 30, 2025. On August 1, 2025, BCAR completed its initial public offering.

“IRS” means the U.S. Internal Revenue Service.

“LLM” means large language model.

“Merger Consideration” means 50,000,000 shares of PubCo Common Stock.

“Merger Sub” means D. Boral Arc Merger Sub Inc., a Delaware corporation and a wholly-owned subsidiary of BCAR.

“Nasdaq” means The Nasdaq Stock Market LLC.

“Nasdaq Global Market” means the Global Market tier of Nasdaq.

“Nasdaq Proposal” means the proposal to be considered at the Extraordinary General Meeting to approve the issuance of PubCo Common Stock and PubCo Warrants in connection with the Business Combination, for purposes of complying with the applicable provisions of Nasdaq Stock Exchange Listing Rule 5635.

“Organizational Documents Proposal” means the proposal to be considered at the Extraordinary General Meeting to approve by ordinary resolution the Proposed Charter and the Proposed Bylaws. A copy of each of the Proposed Charter and the Proposed Bylaws is attached to this proxy statement/prospectus as Annex B-1 and Annex B-2, respectively.

“Person” means any individual, firm, corporation, partnership, limited liability company, association, trust, joint venture, joint stock company, governmental authority or instrumentality or other entity or organization of any other kind.

“Private Placement Shares” or “Private Shares” means the BCAR Class A Ordinary Shares included in the Private Units.

“Private Placement Warrants” means the warrants included in the Private Units, each whole warrant exercisable for one BCAR Class A Ordinary Share at a price of $11.50 per share.

“Private Units” means the 200,000 units of BCAR, consisting of one BCAR Class A Ordinary Share and one-half of one warrant, issued in a private placement that closed concurrently with the IPO.

“Proposed Bylaws” mean the proposed bylaws of PubCo to be in effect following the Domestication Merger and Business Combination, a form of which is attached to this proxy statement/prospectus as Annex B-2.

“Proposed Charter” means the proposed certificate of incorporation of PubCo to be in effect following the Domestication Merger and the Business Combination, a form of which is attached to this proxy statement/prospectus as Annex B-1.

“Proposed Organizational Documents” means the Proposed Charter and the Proposed Bylaws.

“PubCo” means D. Boral ARC Merger Corporation following its merger with BCAR (which will be renamed “Exascale Labs Holdings Inc.”).

“PubCo Board” means the board of directors of PubCo subsequent to the Closing.

“PubCo Class A Ordinary Common Stock” means the Class A Ordinary Common Stock, par value $0.0001 per share, of PubCo, with each such share having one (1) vote per share.

“PubCo Class B Super Common Stock” means the Class B Common Stock, par value $0.0001 per share, of PubCo, with each such share having twenty (20) votes per share.

“PubCo Common Stock” means PubCo Class A Ordinary Common Stock and PubCo Class B Super Common Stock.

“PubCo Preferred Stock” means the preferred stock of PubCo, par value $0.0001 per share.

“PubCo Warrant” means a BCAR Warrant that will become exercisable for one share of PubCo Class A Ordinary Common Stock subsequent to the Closing.

“Public Shareholders” means the holders of BCAR Class A Ordinary Shares that were sold in the IPO (whether they were purchased in the IPO or thereafter in the open market).

“Public Shares” means the BCAR Class A Ordinary Shares sold in the IPO (whether they were purchased in the IPO as part of the BCAR Units or thereafter in the open market) and, following the Domestication Merger, the shares of PubCo Class A Ordinary Common Stock received in connection with the Domestication Merger upon conversion of such BCAR Class A Ordinary Shares.

“Public Warrant Holders” means the holders of the Public Warrants of BCAR.

“Public Warrants” means the BCAR Warrants sold in the IPO (whether they were purchased in the IPO as part of the BCAR Units or thereafter in the open market).

“Record Date” means [_], 2026.

“Representative Shares” means the 1,000,000 BCAR Class A Ordinary Shares granted to D. Boral Capital LLC, the underwriter in BCAR’s initial public offering, as compensation.

“SAFE” means the Simple Agreements for Future Equity by and between Exascale and each Exascale Safeholder.

“Sarbanes-Oxley Act” means the Sarbanes-Oxley Act of 2002.

“SEC” means the U.S. Securities and Exchange Commission.

“Securities Act” means the U.S. Securities Act of 1933, as amended.

“Sponsor” means MFH 1, LLC, a Delaware limited liability company.

“Sponsor Support Agreement” means the Sponsor support agreement, dated as of January 11, 2026, entered by and among BCAR, Exascale and the Sponsor, as it may be amended and supplemented from time to time, pursuant to which the Sponsor has agreed, among other things, to vote in favor of the adoption and approval of the Business Combination. A copy of the Sponsor Support Agreement is attached to this proxy statement/prospectus as Annex D.

“Transfer Agent” means Odyssey Transfer and Trust Company.

“Warrant Agreement” means the Warrant Agreement, dated as of July 30, 2025, between BCAR and Odyssey Transfer and Trust Company, as warrant agent, which governs BCAR’s outstanding warrants.

“Working Capital Loan” means any financing provided by the Sponsor or an affiliate of the Sponsor, or BCAR’s officers and directors, as may occur, in order to finance the transaction costs of the Business Combination.

MARKET AND INDUSTRY DATA

We are responsible for the disclosure contained in this proxy statement/prospectus. However, information contained in this proxy statement/prospectus concerning the market and the industry in which Exascale competes, including its market position, general expectations of market opportunity, size and growth rates, is based on information from various third-party sources, on assumptions made by Exascale based on such sources and Exascale’s knowledge of the markets for its services and solutions. This information and any estimates provided herein involve numerous assumptions and limitations, and third-party sources generally state that the information contained in such source has been obtained from sources believed to be reliable. The industry in which Exascale operates is subject to a high degree of uncertainty and risk. As a result, the estimates and market and industry information provided in this proxy statement/prospectus are subject to change based on various factors, including those described in “Cautionary Note Regarding Forward-Looking Statements” and “Risk Factors — Risks Related to Exascale” and elsewhere in this proxy statement/prospectus.

TRADEMARKS, TRADE NAMES AND SERVICE MARKS

This proxy statement/prospectus contains references to trademarks, trade names and service marks. Solely for convenience, trademarks, trade names and service marks referred to in this proxy statement/prospectus may appear without the ® or ™ symbols, but such references are not intended to indicate, in any way, that the applicable licensor will not assert, to the fullest extent under applicable law, its rights to such trademarks, trade names and service marks. Neither BCAR nor Exascale intends the use or display of other entities’ trade names, trademarks or service marks in this proxy statement/prospectus to imply a relationship with, or endorsement or sponsorship of BCAR or Exascale by, any other entities.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus contains forward-looking statements. These forward-looking statements include, without limitation, statements relating to expectations for future financial performance, business strategies or expectations for the businesses of BCAR, Exascale and PubCo, and the timing and ability of BCAR and Exascale to complete the Business Combination. These statements constitute projections, forecasts and forward-looking statements, and are not guarantees of performance. Such statements can be identified by the fact that they do not relate strictly to historical or current facts. When used in this proxy statement/prospectus, words such as “anticipate”, “believe”, “can”, “continue”, “could”, “estimate”, “expect”, “forecast”, “intend”, “may”, “might”, “plan”, “possible”, “potential”, “predict”, “project”, “seek”, “should”, “strive”, “target”, “will”, “would” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking.

Forward-looking statements in this proxy statement/prospectus and in any document incorporated by reference in this proxy statement/prospectus may include, for example, statements about:

These forward-looking statements are based on information available as of the date of this proxy statement/prospectus and BCAR’s and Exascale’s managements’ current expectations, forecasts and assumptions, and involve a number of judgments, known and unknown risks and uncertainties and other factors, many of which are outside the control of BCAR, Exascale and their respective directors, officers and affiliates. Accordingly, forward-looking statements should not be relied upon as representing BCAR’s or Exascale’s views as of any subsequent date. Neither BCAR nor Exascale undertakes any obligation to update, add or to otherwise correct any forward-looking statements contained herein to reflect events or circumstances after the date they were made, whether as a result of new information, future events, inaccuracies that become apparent after the date hereof or otherwise, except as may be required under applicable securities laws.

You should not place undue reliance on these forward-looking statements in deciding how your vote should be cast or in voting your shares on the proposals set out in this proxy statement/prospectus. Should one or more of a number of known and unknown risks and uncertainties materialize, or should any of BCAR’s and Exascale’s assumptions prove incorrect, actual results or performance may be materially different from those expressed or implied by these forward-looking statements. Some factors that could cause actual results to differ include, but are not limited to:

QUESTIONS AND ANSWERS FOR SHAREHOLDERS OF BCAR

The questions and answers below highlight only selected information from this document and only briefly address some commonly asked questions about the proposals to be presented at the Extraordinary General Meeting, including with respect to the Business Combination. The following questions and answers do not include all the information that is important to BCAR’s shareholders. BCAR urges shareholders to read this proxy statement/prospectus, including the Annexes and the other documents referred to herein, carefully and in their entirety to fully understand the Business Combination and the voting procedures for the Extraordinary General Meeting, which will be held at 10:00 A.M., Eastern Time, on [_], 2026, at the offices of Loeb & Loeb LLP, 345 Park Avenue, New York, NY 10154. You may also attend the Extraordinary General Meeting virtually via telephone at: Telephone number: __________________ Participant Passcode: __________________. For the purposes of British Virgin Islands law and the Current Charter (as defined herein), the physical location of the Extraordinary General Meeting will be at the offices of Loeb & Loeb LLP, 345 Park Avenue, New York, NY 10154. If you hold your shares through a bank, broker or other nominee, you will need to take additional steps to participate in the Extraordinary General Meeting, as described in this proxy statement/prospectus.

BCAR shareholders are being asked to consider and vote upon, among other proposals, a proposal to approve and adopt the Business Combination Agreement and approve the Business Combination. The Business Combination Agreement provides for, among other things, (i) the Domestication Merger of BCAR and (ii) the merger of Merger Sub with and into Exascale, with Exascale surviving the merger, in accordance with the terms and subject to the conditions of the Business Combination Agreement, as more fully described elsewhere in this proxy statement/prospectus. See “The Business Combination Proposal” and “The Domestication Merger Proposal” for more detail. The BCAR Board is soliciting your proxy to vote for the Business Combination and other proposals at the Extraordinary General Meeting because you owned BCAR Class A Ordinary Shares at the close of business on [_], 2026, the “Record Date” for the Extraordinary General Meeting, and are therefore entitled to vote at the meeting. This proxy statement/prospectus summarizes the information that you need to know in order to cast your vote.

A copy of the Business Combination Agreement is attached to this proxy statement/prospectus as Annex A and you are encouraged to read it in its entirety.

THE VOTE OF PUBLIC SHAREHOLDERS IS IMPORTANT. PUBLIC SHAREHOLDERS ARE ENCOURAGED TO VOTE AS SOON AS POSSIBLE AFTER CAREFULLY REVIEWING THIS PROXY STATEMENT/PROSPECTUS, INCLUDING THE ANNEXES AND THE ACCOMPANYING FINANCIAL STATEMENTS OF BCAR AND EXASCALE.

If BCAR’s shareholders do not approve each of the Condition Precedent Proposals, then unless certain conditions in the Business Combination Agreement are waived by the applicable parties to the Business Combination Agreement, the Business Combination Agreement could be terminated and the Business Combination may not be consummated. See “The Business Combination Proposal,” “The Domestication Merger Proposal,” “The Organizational Documents Proposal,” “The Directors Proposal,” “The Equity Incentive Plan Proposal,” and “The Nasdaq Proposal,” of this proxy statement/prospectus, respectively.

BCAR will hold the Extraordinary General Meeting to consider and vote upon these proposals. This proxy statement/prospectus contains important information about the Business Combination and the other matters to be acted upon at the Extraordinary General Meeting. Shareholders of BCAR should read it carefully.

After careful consideration, the BCAR Board has determined that each of (i) the Business Combination Proposal, (ii) the Domestication Merger Proposal, (iii) the Organizational Documents Proposal, (iv) the Advisory Organizational Documents Proposals, (v) the Directors Proposal, (vi) the Equity Incentive Plan Proposal, (vii) the Nasdaq Proposal, and (viii) the Adjournment Proposal, if presented, are in the best interests of BCAR and its shareholders and unanimously recommends that you vote or give instruction to vote “FOR” each of those proposals.

If BCAR’s shareholders do not approve each of the Condition Precedent Proposals, then unless certain conditions in the Business Combination Agreement are waived by the applicable parties to the Business Combination Agreement, the Business Combination Agreement could terminate and the Business Combination may not be consummated.

The existence of financial and personal interests of one or more of BCAR’s directors may result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of BCAR and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, BCAR’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. See “The Business Combination Proposal — Certain Interests of BCAR’s Directors and Officers and Others in the Business Combination” for a further discussion of these considerations.

Exascale is a next-generation AI infrastructure provider operating an asset-light, software-defined GPU compute platform and related AI infrastructure solutions. Exascale’s core business includes GaaS, through which it provides reserved and on-demand access to high-performance GPU compute capacity sourced from third-party data centers globally, as well as GPU cluster management and optimization services for AIDC operators. In addition, Exascale has developed certain modular data center, high-density liquid cooling, HVDC power and energy storage solutions that are designed to address deployment bottlenecks in AI infrastructure and that Exascale believes are ready for commercial engagement, although these capabilities have not yet generated revenue as of the date of this proxy statement/prospectus. The platform is purpose-built for large-scale AI workloads, including LLM training, fine-tuning, and high-concurrency inference. Additional information about Exascale is set forth in the section titled “Information about Exascale” in this proxy statement/prospectus.

Based on BCAR’s due diligence investigations of Exascale and the industry in which it operates, including the financial and other information provided by Exascale in the course of BCAR’s due diligence investigations, the BCAR Board believes that the Business Combination with Exascale is in the best interests of BCAR and its shareholders, and presents an opportunity to increase shareholder value. However, there is no assurance that the Business Combination with Exascale will increase shareholder value. See “The Business Combination Proposal — BCAR Board of Directors’ Reasons for the Approval of the Business Combination” for additional information.

Although the BCAR Board believes that the Business Combination with Exascale presents an attractive business combination opportunity and is in the best interests of BCAR and its shareholders, the BCAR Board did consider certain potentially material negative factors in arriving at that conclusion. These factors are discussed in greater detail in “The Business Combination Proposal — BCAR Board of Directors’ Reasons for the Approval of the Business Combination,” as well as in “Risk Factors — Risks Related to Exascale.”

The allocation of the 50,000,000 shares of PubCo Common Stock among Exascale Securityholders will be determined in accordance with (i) the conversion provisions applicable in the event of a “liquidity event” under the SAFEs, (ii) the terms of the Base Camp Investment Agreement, and (iii) the allocation percentages applicable to the Exascale Equity Incentive Recipients and Exascale stockholders. As a result, the allocation of the Merger Consideration among Exascale Securityholders is not determined using a single uniform exchange ratio applicable to all Exascale securities.

At the closing of the Acquisition Merger, each issued and outstanding SAFE will be cancelled and converted into the right to receive a number of shares of PubCo Class A Ordinary Common Stock based on the SAFE’s “implied ownership percentage,” as determined under the terms of the applicable SAFE in connection with the Business Combination, which constitutes a “liquidity event” under the SAFEs. In general, a SAFE’s implied ownership percentage is the product of (i) the quotient obtained by dividing (x) the SAFE’s purchase amount by (y) the SAFE’s post-money valuation cap, multiplied by (ii) 100; subject to the capitalization adjustments, rounding provisions, and other terms contained in the applicable SAFE and the final closing calculations. The resulting implied ownership percentage determines the number of shares of the 50,000,000 Merger Consideration issuable for each SAFE. Based on the foregoing, the aggregate implied ownership percentage of all SAFEs outstanding on the filing date of this proxy statement/prospectus was 17.533%, entitling all the SAFEs to collectively receive an aggregate of 8,766,500 shares of PubCo Class A Ordinary Common Stock as their portion of the Merger Consideration in connection with the consummation of the Business Combination. The right of an Exascale Safeholder to receive PubCo Class A Ordinary Common Stock for their SAFE will be contingent on the execution by such Exascale Safeholder of an acknowledgement and such other agreements and other documents as Exascale deems necessary, appropriate or expedient.

At the closing of the Acquisition Merger, the Base Camp Investment Agreement will be cancelled and converted into the right to receive a number of shares of PubCo Class A Ordinary Common Stock based on the “implied ownership percentage” attributable to the Base Camp Investment Agreement. The implied ownership percentage applicable to the Base Camp Investment Agreement is a fixed percentage determined in accordance with the terms of the Base Camp Investment Agreement and will equal 0.625%, entitling the Base Camp Investor to receive an aggregate of 312,500 PubCo Class A Ordinary Common Stock as their portion of the Merger Consideration in connection with the consummation of the Business Combination.

At the closing of the Acquisition Merger, each then outstanding Exascale Equity Incentive award will be cancelled and converted into the right to receive a number of shares of PubCo Class A Ordinary Common Stock based on the “implied ownership percentage” attributable to the award. The implied ownership percentage of the Exascale Equity Incentive awards is determined based on Exascale’s fully diluted capitalization, and, based on Exascale’s capitalization as of the filing date of this proxy statement/prospectus, will be 0.154%, entitling the Exascale Equity Incentive Recipients to receive an aggregate of 77,000 PubCo Class A Ordinary Common Stock as their portion of the Merger Consideration in connection with the consummation of the Business Combination.

At the closing of the Acquisition Merger, each issued and outstanding Exascale Class A common stock will be cancelled and converted into the right to receive a number of shares of PubCo Class A Ordinary Common Stock based on the “implied ownership percentage” attributable to Exascale’s Class A common stock. The implied ownership percentage of the Exascale Class A common stock is determined based on Exascale’s fully diluted capitalization, and, based on Exascale’s capitalization as of the filing date of this proxy statement/prospectus, will be 20.200%, entitling the holders of Exascale Class A common stock to receive an aggregate of 10,100,000 PubCo Class A Ordinary Common Stock as their portion of the Merger Consideration in connection with the consummation of the Business Combination.

At the closing of the Acquisition Merger, each issued and outstanding Exascale Class B common stock will be cancelled and converted into the right to receive a number of shares of PubCo Class B Super Common Stock based on the “implied ownership percentage” attributable to Exascale’s Class B common stock. The implied ownership percentage of the Exascale Class B common stock is determined based on Exascale’s fully diluted capitalization, and, based on Exascale’s capitalization as of the filing date of this proxy statement/prospectus, will be 61.488%, entitling the holders of Exascale Class B common stock to receive an aggregate of 30,744,000 PubCo Class B Ordinary Common Stock as their portion of the Merger Consideration in connection with the consummation of the Business Combination.

At the Effective Time, the holders of Exascale Common Stock, the Exascale Safeholders, the Base Camp Investor, and the Exascale Equity Incentive Recipients will cease to have any rights with respect to Exascale securities, except the right to receive their portion of the Merger Consideration.

The allocation of the 50,000,000 shares of PubCo Class A Common Stock is set forth below (based on Exascale’s capitalization as of the filing date of this proxy statement/prospectus):

The foregoing discussion and figures are provided to illustrate the allocation mechanics, and remain subject to final rounding and closing adjustments.

At any time at or prior to the Extraordinary General Meeting, during a period when they are not then aware of any material nonpublic information regarding BCAR or its securities, our Sponsor, officers, directors and/or their affiliates, in compliance with the tender offer rules and other Exchange Act limitations, including Rule 14e-5 thereunder, may purchase Public Shares from institutional and other investors, execute agreements to purchase shares from such investors in the future, or they may enter into transactions, including non-redemption agreements, with such investors and others to provide them with incentives to acquire shares of BCAR and/or not to redeem (or to validly rescind any redemption requests). Our Sponsor, officers, directors and/or their affiliates anticipate that they may identify such unaffiliated third-party shareholders with whom our Sponsor, officers, directors or their affiliates may pursue privately negotiated transactions by either the shareholders contacting us directly or by our receipt of redemption requests submitted by shareholders following our mailing of proxy materials in connection with the Business Combination. To the extent that our Sponsor, officers, directors, advisors or their affiliates enter into a private transaction with an unaffiliated third party, they would identify and contact only potential selling or redeeming shareholders who have expressed their election to redeem their shares for a pro rata share of the trust account, whether or not such shareholder has already submitted a proxy with respect to the Business Combination but only if such shares have not already been voted at the Extraordinary General Meeting. Our Sponsor, executive officers, directors, advisors or their affiliates will select which shareholders to purchase shares from based on the negotiated price and number of shares and any other factors that they may deem relevant, and will be restricted from purchasing shares if such purchases do not comply with Regulation M under the Exchange Act and the other federal securities laws. Any such privately negotiated transactions may be effected at purchase prices that are no greater than the per share pro rata portion of the trust account. Such privately negotiated transactions may include a contractual acknowledgement that such unaffiliated third-party shareholder, although still the record or beneficial holder of our shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights. In the event that our Sponsor, officers, directors and/or their affiliates purchase shares in privately negotiated transactions from unaffiliated third-party shareholders who have already elected to exercise their redemption rights, such selling shareholders would be required to revoke their prior elections to redeem their Public Shares. The purpose of such share purchases and other transactions would be to limit the number of Public Shares electing to be redeemed.

In accordance with the SEC’s Compliance and Disclosure Interpretation 166.01, any Public Shares purchased by our Sponsor, officers, directors and/or their affiliates would not be voted in favor of approving the Business Combination.

Except as disclosed in this proxy statement/prospectus, we have not entered into any privately negotiated transactions with respect to our shares as of the date hereof. If they engage in such privately negotiated transactions, our Sponsor, officers, directors and/or their affiliates will be restricted from making any such purchases when they are in possession of any material non-public information not disclosed to the seller or if such purchases are prohibited by Regulation M under the Exchange Act.

Our Sponsor, officers, directors and/or their affiliates will be restricted from making purchases of shares if the purchases would violate Section 9(a)(2) or Rule 10b-5 of the Exchange Act. We expect any such purchases would be reported by such person pursuant to Section 13 and Section 16 of the Exchange Act to the extent such purchasers are subject to such reporting requirements. Additionally, in the event our Sponsor, directors, executive officers, advisors, or their affiliates were to purchase shares or warrants from Public Shareholders, or if any third party investors are incentivized to acquire Public Shares by our Sponsor, directors, executive officers, or their affiliates, such purchases would be structured in compliance with the requirements of Rule 14e-5 under the Exchange Act including, in pertinent part, through adherence to the following:

None of the funds in the trust account will be used to purchase Public Shares in such transactions.

The following summarizes the pro forma ownership of PubCo Class A Ordinary Common Stock and PubCo Class B Super Common Stock immediately following the Business Combination across a range of varying redemption scenarios.