I was out doing airwork today in my TR182, and I tried using the ailerons (gently) in a full stall (yoke held fully back). As I expected (I've never tried before) the ailerons work normally.
Again, this is my understanding of the ATPL text. The ailerons may still work; straight wings generally stall at the root first. Generally speaking swept and taper wings stall tip first. I can imagine the problems created by a tip stall in the flare. Regardless, there is a theoretical danger (not managed to experience this yet) that the down going aileron will take the angle of attack beyond crit and stall the up going wing. May I refer you to my earlier comment on wing down landings?
Just to add, I witnessed the result of what I understand to be a stall in the flare this weekend - a PA38. Nose drop in flare, collapsed nose wheel...prop strike. Comments were made about the T-tail (not flown the type), beyond a certain AoA, being completely ineffective.