While I agree it is irksome to have to go through the process amongst every new community how are individual groups to know that a new user amongst them is a trusted user elsewhere? I am in several different communities and for some I use the same user id but for others I do not. Indeed for a couple I did not register for an account amongst a few communities with the same email address. I know it is “me” but none of the communities do; other than one admin who commented in their community about something I also posted here!
What would happen when a user joins one community in their professional role and another for personal use? Should both of those garner the same trust?