[transmetahuman]

I might look at a slightly modified form of the Uncontrollable limitation on just the Mind Reading part of the ability to signify that occasional mental "shout".

Maybe Uncontrollable Appetite (Minds) (only when in gestalt: some accessibility limitation) for that aspect?

My only other immediate thought is that an uncontrolled gestalt mind might logically leave the telepath with bits of the other person's personally too.