Typically with many radios the use of a flaperon mix using only two surfaces on the wing will require considerable end point reductions. Although I cannot speak for Spectrum. Actually since you chose to post this in the beginners forum I would suggest that flaperons are a very poor idea for beginners and it will only prolong your learning curve and possibly make it more expensive in terms of damaged aircraft.

True flaperons with only two surfaces is bad idea in the learning environment.

John