Understood.

This isn't for me as it is, but I can imagine how you can evolve it by using remote key signing like the nostr:npub10efcj7x65z2ak6vd69xr8f2hvqwuaqrhlygl3yqa4y63hfvc02mqwzaeh3 remote signer, or key rotation, which I'm currently write a NIP for.

Delegated authority is coming soon to NOSTR, I think this is when your service will be feasible.

I would definitely fix the URL inclusion issue, even for you Bitcoin Archive client, that definitely makes it unusable.