I've got a couple planes with flaperons and I use them backwards - as reflex - to force the plane down as my planes tend to be pretty light floaters. By adding reflex they're easier to land.
Now if I had a biplane with four full span ailerons and four servos I might try a form of butterfly where two ailerons go up and two ailerons go down just to see what happens. But I would try it at fairly high altitude expecting some nasty stall behavior.