I mix the flapperons to follow the elevators proportionally. I use a switch to turn them on and off. I try to mix them so that they travel about 70% of the distance of the elevators. Not a 70% mix, I just eyeball 70% or 75% of the actual movement. Some people prefer about half of the elevator throw. If I pull full 45 degrees of up elevator, they are in the 30ish degree range.

I use them only to take off. I give full power, and after about 5 feet of roll, I'll pull a small amount of elevator, with flapperon, and the Mini jumps about 10 feet up off of the ground. I then turn the flapperons off. It takes much more run up without the flapperons.