I'm not sure that's the best answer but GrapheneOS has a page they recommend linking to developer that may be interested in supporting something else than Play

I'm not sure that's the best answer but GrapheneOS has a page they recommend linking to developer that may be interested in supporting something else than Play Integrity: https://grapheneos.org/articles/attestation-compatibility-guide https://grapheneos.org/articles/attestation-compatibility-gu...