I hear a lot of warnings about not using the flapperon feature and I am not sure if that is just because they are tricky to set up well, or if they really do no good at all.

If set up correctly will they actually reduce stall speed and allow for slower and shorter landings? If so then I think they would be a good feature for my model.

People say flapperons will cause tip stalls, but obviously if they were flying faster their plane would not have stalled. I am not sure if people are stalling due to pilot error or if flapperons really make stalling more sudden?

If flapperons are useful feature I should I set them to go up like spoilers, or go down like flaps and how much up/down, should I try? I have a Phoenix Strega 40, basically a scale P-51 Mustang.