I certainly agree that that is possible. However airplanes designed in compliance with FAR part 23 (all full-scale general aviation aircraft) must meet the stall characteristics quoted below. None that I have flown, nor any that I can bring to mind have gone to a configuration other than plain flap type ailerons in order to avoid aileron reversal at the stall. In other words, though what you describe is possible, it isn’t a very common phenomenon. I stand by my opinion that though there are certainly other causes, the most common cause of so called “tip stall” is inadequate compensation for adverse yaw when operating near the stall angle.