I don't get it...
Why do you still need PGP at all? nostr:nprofile1qqs83nn04fezvsu89p8xg7axjwye2u67errat3dx2um725fs7qnrqlgpzamhxue69uhhxetpwf3kstnwdaejuar0v3shjtc3uszjr does software signing better anyhow.
And what's the difference of using nostr as your long term identity key and not just a PGP master key? At least the PGP master key you can revoke, expire, rotate, while we don't have any of that in nostr yet.