@simon_brooke One simple approach we could copy from Bluesky:
– Optional: a domain name as a user ID.
– At the domain, a document (either a DNS record or a file at a well-known location) points to the (local) server ID.
– The local profile points back to the domain name.
@rauschma That's an awful lot of complexity which gets you back to the same dilemma you had in the first place: either the user owns their own domain name (hosted on the domain name system) *and* a server they can point that domain name at; or they're dependent on someone else to host it.
I don't think you win anything at all.