The biggest problem with having the aileron sticking out past the wingtip on a trainer is that just about everything you try to go past will snag on it, and try to rip the aileron off. If you cartwheel, you can be pretty sure the aileron will take damage.

In the air, it won't affect anything on an LT-40.

On faster planes, an overly long aileron like that can contribute to flutter, but that's really the worst of it.