Frostr does not require any nostr protocol changes, it can integrate with NIP-07 and NIP-46. What we need to do is finish our reference signing clients (so other signers can understand and implement it themselves) and then after that create a spec for Bifrost the underlying library that powers the implementation into a signing client (if someone wants to reimplement to create their own library) But none of this changes or requires anything new of the nostr specs