I think the twin analysis board concept would benefit if the comment box and analysis boards were instantaneous like msn messenger (so manual refreshing was not need, but each player still has to submit moves, variations and comments). And instead of a take back option both players could agree to go to change the board setup to any position, whether it is 5 or 8 moves back or to a position at the end of a variation that either of them previously posted.
What about a method for setting up live coaching/unrated game appointments? They could just message each other normally to arrange this instead though.
i agree, then if someone is losing, they will just go back to the starting position and you lose your train of thought