I played with flaperons on a glider in the past and tried it a few years later with an ARF shoulder wing sport model. Up to about 10 degrees down helps the lift a lot on the glider and a touch on the ARF with it's narrow strip ailerons compared to the glider. Niether model showed any sign of tip stalling (Sorry Paul). Assuming your model uses strip ailerons there is no problem at all with using the clevis links to adjust in some droop. All you're doing is adding camber to the airfoil. Don't go more than 10 degrees though or you'll find you have too much adverse yaw to enter turns smoothly without using rudder coordinated in with the ailerons. 5 to 7 is probably the best bang for the buck all 'round.

But if this is conventional outboard ailerons then don't do it. Tips stalls will almost certainly occur.