I can’t see how a dealer can get a black mark if a scheme customer cancels the order prior to taking delivery or if the car is returned early for one of numerous reasons beyond the dealers control. Motability have always locked in the AP at time of order, I can’t see this ever changing.
They don’t get a black mark if a customer cancels, but they can when they alter the AP, not that most seem to worry about it. Motability have a ‘fines’ system which reduces dealerships commission, and altering APs is one of the ‘offences’, although given that most do it they don’t seem to be too worried about it (or they perhaps do it in a way that doesn’t raise a flag)