If the secondary effect of aileron was yaw in the same direction as the intended roll, when you roll wings level, the aircraft should yaw to the left. It wont though
Oh, yes it will! If, from a level
balanced 30° AOB turn to the right, left aileron is applied (to roll the aircraft towards wings level) without any movement of the rudder, the aircraft will also yaw to the left as a consequence of the applied aileron.