However, how do you know how much of the wing is stalled, so assume the worst and avoid the use of aileron until unstalled.
It is a matter of feel. On the military jets of the 70/80s, the F4 Phantom and the Lightning any max rate turn required flying in the buffet. Too much and the drag increased too much and you stopped turning. Too little and the turn radius increased. It starts with light buffet and gradually gets heavier. Not much to do with the original question I admit but in the Phantom light buffet had to be pulled on the finals turn as the wing did not work too well at low speeds!