I like it in the reverse, but not how you put it, i.e. im able to generate sub ID's for various purposes on the fly that a client/signer is able work with via derivation; making me just having to handle 1 keypair (with the trade off that in case of compromise/loss, i fuck up all that stuff as well) The main issue with what you are proposing is that it breaks the assumption much of everything works on here, and that is everything resolves around a particular npub. Instead, you put in this extra step required having to run some xpub derivation stuff to see if some pubkey potientially means something else i would otherwise not be aware of. So in other words, what on earth do i query if i look for your stuff? Do i query a range of derivations? Do relays do that for you? You just broke the whole straightforward pointer basically