@jana @MagicLike I'd be hesitant to support it, due to Libreboot's Binary Blob Reduction Policy:
https://libreboot.org/news/policy.html
Under this policy, it says: if a blob can be avoided, avoid it.
It makes a special exception for dGPU ROMs though. Anyway, you need to extract a VGA ROM and insert it in flash, to use the dGPU. Also, relevant commit:
https://browse.libreboot.org/lbmk.git/commit/?id=9dc3c86ae37db781b6bc4e745a57217c3511074b
You could adapt a reverse of this diff, to handle the Nvidia ROM; kinda works with nouveau on linux 6.8 to 6.9, but very very buggy.