I think an amazing feature would be to let people easily peer role based ACL memberships between software.
basically "what if SCIM, but across fediverse stuff?"
like, if you have a bunch of users on discord, but you want to seamlessly line up their roles with one on github, it sucks.
but maybe it could be AWESOME in something like #bonfire + #forgejo , or #opencollective + #vervis
and maybe you could accomplish this with the basic FEP SSO stuff we have around right now, or basic OIDC/Oauth,
but it would be super neat to communicate updates in group membership across activitypub.
is it just re-inventing SCIM/PAM? sure. but would it be awesome? also yes.
it should probably communicate the fedi handle, not the user's email, for privacy reasons.
imagine being able to join /one/ of /any/ community tools, and the process letting you swap between using many peripheral tools (having it only work inside e.g. @bonfire would lock things down too much, vs bidirectional grouping in e.g. #metagov )