So I'm working on the ability to support custom domains as usernames in Loops.
You would bring your own domain, point it towards the loops server with a TXT verification record, and it would handle it accordingly.
If you decide to migrate away, an easy process would migrate everything.
While preserving your existing content permalinks!
Spooky action at a distance, or quantum federation (a prettier term for universal identities)
@dansup that would be wild and cool!