Flaps increase the amount of lift to your wing without increasing the angle of attack of your wing. If anything your wing develops more lift at a lesser angle of attack, thereby decreasing the probability of a tip stall.
Someone step in here if I'm wrong, but doesn't taking off with flaps usually
increase the chances of a tip stall? While I do agree that in the hands of a well seasoned warbird pilot this shouldn't be a problem, but taking off with flaps is usually gonna put the plane in the air at a much lower airspeed than normal. This in turn would seem to set up the possibility of a tip stall should the wing become out of level as the rest of the wing is not really flying yet. Any aileron input at that point would likely make the situation worse.