With the calls for selective rooms I would say being able to sign in invisibly would be a great fix on the being flooded with messages problem, it would be a simple implement and I think at this point it wouldn't hurt AChat all that much.If they want visible chatters they could have you invisible when in Character Editor and visible when in Partner Search.
This would be a big deal for us. It should be simple to implement. If you login you are automatically in the editor mode. You are invisible as long as you are there. When you go to "search" or "show myself" you are visible.