Maybe I can talk to the alignment guy about where they were lifting it and show him in the manual.
When they say the tires are starting to cup, it's when looking at the side of the tire treads (looking at the side of the vehicle), each tread starts off high and goes lower, then the next one is high and back down again. If you were to wrap a string around the circumferance of the tire it would only hit the leading edge of each individual tread. I believe it's a toe in type issue and caused by the scuffing it produces.