Material Agreement, Amendments to Bylaws (Form 8-K)

Item 1.01 Entry into a Material Definitive Agreement.

Non-Redemption Agreements

As previously disclosed in a Current Report on Form 8-K filed by GP-Act III Acquisition Corp., a Cayman Islands exempted company (the "Company"), with the U.S. Securities and Exchange Commission (the "SEC") on November 10, 2026, the Company and GP-Act III Sponsor LLC, a Cayman Islands limited liability company and the Company's sponsor ("Sponsor HoldCo"), entered into agreements (collectively, the "Non-Redemption Agreements") with one or more third-party shareholders of the Company (each, an "Investor") in exchange for such Investors agreeing (i) not to redeem (or to validly rescind any redemption requests previously made in respect of) an aggregate of 2,525,000 of the Company's Class A ordinary shares, par value $0.0001 per share (the "Class A ordinary shares"), included in the units sold in the Company's initial public offering (such shares subject to the Non-Redemption Agreements, the "Non-Redeemed Shares"), in connection with the Extraordinary General Meeting (as defined below), and (ii) to vote (in person or by proxy), or provide consent with respect to, all Non-Redeemed Shares owned by such Investors as of the record date in favor of the Extension Amendment Proposal and the Trust Amendment Proposal (each as defined below) at the Extraordinary General Meeting.

Pursuant to the Non-Redemption Agreements, Sponsor HoldCo has agreed to transfer to such Investors an aggregate of 505,000 existing Class A ordinary shares held by Sponsor HoldCo that were issued upon the conversion of its Class B ordinary shares promptly following the closing of the Company's initial business combination, conditional on, among other matters, (i) such Investors not exercising (or having validly rescinded any prior exercise of) their redemption rights with respect to the Non-Redeemed Shares in connection with the Extraordinary General Meeting, (ii) such Investors voting or consenting in favor of the Extension Amendment and the Trust Amendment at the Extraordinary General Meeting and (iii) the Extension Amendment and the Trust Amendment being approved at the Extraordinary General Meeting.

As previously disclosed, on November 3, 2026, the Company entered into a Business Combination Agreement (the "Business Combination Agreement") with Dronamics Group Limited ("Dronamics"). The Business Combination Agreement permits the Company, Sponsor HoldCo and their respective affiliates to enter into non-redemption agreements in connection with an extension of the deadline by which the Company must consummate its initial business combination, provided that any consideration payable thereunder is borne solely by Sponsor HoldCo. No funds in the Company's trust account will be used to pay any consideration under the Non-Redemption Agreements.

The foregoing summary of the Non-Redemption Agreements does not purport to be complete and is qualified in its entirety by reference to the form of Non-Redemption Agreement, a copy of which was filed as Exhibit 10.1 to the Company's Current Report on 8-K filed with the SEC on November 12, 2026 and is incorporated herein by reference.

Trust Amendment

On November 12, 2026, in connection with the Extraordinary General Meeting, the Company and Continental Stock Transfer & Trust Company (the "Trustee"), entered into Amendment No. 2 to the Investment Management Trust Agreement, dated as of May 8, 2024, as amended by Amendment No. 1 thereto as of May 12, 2026, by and between the Company and the Trustee (as so amended, the "Trust Agreement"), to extend the date on which the Trustee must liquidate the trust account established in connection with the Company's initial public offering (the "Trust Account") if the Company has not completed its initial business combination from November 13, 2026 to May 8, 2027 (the "Trust Amendment"). A copy of the Trust Amendment is attached to this Current Report on Form 8-K as Exhibit 10.1 and incorporated herein by reference.

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

The information disclosed in Item 5.07 of this Current Report on Form 8-K is incorporated by reference into this Item 5.03 to the extent required herein.