Now Nextcloud Social assigns to users automatically a federated ID which corresponds to the username + nextcloud URL combined. This is not always desirable, for example when the URL is not stable etc. Unfortunately the federated ID can not be changed nor deleted and recreated by the user after it has once been created.
Is there some reason why the ID can not be editable by the user? In the long run, I see that the point of a federated ID is to give the user a permanent global ID that should be as permanent as possible, so it would be crucial to give users the possibility to configure the ID in the most flexible way to support maintaining such permanence.
At least personally I can not imagine trying to use federation features in any serious uses until my ID could become stable, including a user name and host URL that will be immune to inevitable diverse server and software configuration changes over future decades.