Hi Actinic,
Don't think that would work...the purpose of a UID is to get the buyer to pay (which they've already done 2 or 3 times
And if mutually agreed is chosen, and the buyer DOESN'T agree (and also has proof of payments and refunds) it just turns into a big mess.
Forgot to add--buyer can still leave FB as long as they respond to dispute. Just no donut and no difference in rating...but the comment would still be there.....