Agree entirely Bear Cub.
I am doing a lot of this at the moment (although I find I do prefer to fly alone!)
When I fly with another pilot, one of us is PIC the way there, the other is PIC on the way back. This covers everything, including plight planning, navigating, working the radio etc.
Ambiguity in this regard is surely a recipe for disaster.
(I haven`t answered the original question either - sorry!)