Must the buyer accept all amendments the sellers make to the TRR if they sign the approved by buyer if list is amended section?

We are selling our house. We've signed a contract. The buyer had an inspection and submitted a Notice of Treatments, Repairs & Replacements. They signed both the "submitted by buyer" and "approved by buyer if list is amended" sections on the same day at the same time prior to us seeing the list, obtaining cost estimates, and negotiating the costs above our agreed upon TRR cost cap. Since he already signed approving the list if amended, does that mean he must accept any and all amendments we make to the list AND does his signature waive his right to negotiate the TRR?