Would something bad happen if I change the ID URIs for things on my friends.grishka.me #Smithereen instance? I don't like identifying users by username only. Numeric IDs would be better in the long run and would allow for changeable usernames. Humans won't see them anyway unless they're very curious.
Anyway, is there a way to tell those three Mastodon instances to change the IDs of my users? How much will break if I just change the URIs?
@grishka
Changing usernames is a big no-no, as far as I know. Not the least, because it makes the system vulnerable to impersonation. Also, imagine all Mastodon, Pleroma, Friendica instances having to rewrite posts as soon as someone changes usernames.
Don't do it.