The problem as I understand it is basically that user IDs in ActivityPub are intrinsically tied to the domain on which the user registered, so you can’t really move a user from one domain to another.
Well no they can’t, because that’s not part of ActivityPub. In fact ActivityPub mandates HTTP URLs. Of course, any extension can choose to change that, but since nobody is actually supporting magnet links, it’s not relevant.
The problem as I understand it is basically that user IDs in ActivityPub are intrinsically tied to the domain on which the user registered, so you can’t really move a user from one domain to another.
It’s not true, all ActivityPub IDs are URIs
Yes exactly - those URLs contain the domain name, so you can’t change servers for a user as their ID is tied to the domain.
They can be URNs (like magnet:), as shown above.
Well no they can’t, because that’s not part of ActivityPub. In fact ActivityPub mandates HTTP URLs. Of course, any extension can choose to change that, but since nobody is actually supporting magnet links, it’s not relevant.