Yes, that was the way I came up with it last time I was thinking about key rotation, derivation, subkeys, etc. Instead of making it a standard (which is difficult and hard to agree on), just play by your own rules and create your own signing schemes, derive any amount of keys, etc. No one needs to know anything because, in the end, everything gets signed with your "canonical" keys, so there aren't any new features that client devs needs to take care about. On the other side, the only standard that I think might be valuable for this case of key rotation is social proofs, as other keys attesting/signaling that you rotated. It's the same principle as the wot in PGP, and in Nostr, it could be achieved out of the box. I really want to put together a prototype about this. Maybe I'll have some time soon...