I realize I'm getting older and set in my ways, but I still think the problem has to either be the calipers not allowing the brake pads to retract or the rotors are just bad from the factory. True, if the mounting surface is uneven or corroded, and the mounting bolt torque for the rotors is uneven, it could cause a problem, but all things being equal, rotors usually warp due to excessive heat. That would be caused by the brake pads dragging.
I guess I sort of have an advantage, as I must push my TA around in the garage in order to turn it around to go out. I can hear and feel if the brakes are dragging, and a few times I have removed the calipers and cleaned them out with some brake cleaner and after that the dragging was gone. I will be interested to find out what the factory finally tells Adey....