Idea: if you mod a community on a lemmy.somewhere you should be able to migrate it to lemmy.elsewhere which would include all post & comment links being forwarded and subbed users having their subscription updated to reflect the new location.
I’m aware this would be a way down the road as user account migration alone is still not great but it would be a great feature for the fediverse to have to avoid centralisation and mod/server admin wars.
Currently it just means you can post to communities on the servers yours is federated with.
It doesn’t mean you can sign into the other server with your account a la “sign in with Google/Twitter/etc.” That needs to change first.