syntax would be a bit different on the new releases and that would unlock some new options we don't currently have, but there's no behavior that you can get today which you wouldn't be able to get any more under this proposal.
Agreed. Moving the inherit flag to the many-to-many join relation provides flexibility, while representing the present behavior is trivial - every row for a given member role has the same value for said flag.
One seemingly missing feature is to specify for a role that its privileges cannot be inherited. In this case associations where it is the group role mustn't be flagged inherit. Symmetrically, "inherit only" seems like a plausible option for pre-defined group roles.
I agree that granting membership makes the pg_auth_members record appear and revoking membership makes it disappear.
I dislike having GRANT do stuff when membership is already established.
ALTER MEMBER role IN group ALTER [SET | ASSUME] [TO | =] [TRUE | FALSE]
