To be clear.  I propose no change.  The protocol is working.  I propose dont change it, and dont touch it.  Find a NIP work around for one of the other NIPs that's fine.  Let 2s be 2s and 3s be 3s, because we already have a user base of 2s and 3s and cant change that now.  Extending profiles is a good way.  I actually think profiles should be extensible by design, in a permissionless way.