I'd advise against flaperons on any Four-Star. The tapered aileron reduces the effect atthe tips... but full span flaperons is asking for trouble.

To split the ailerons for flaps and ailerons... no problem at all n the 4*60. You would slice the aileron right even with the rib just inboard of the aileron servos (the one RIGHT beside the servo) No change to the aileron servos needed at all.

Come inboard a bay separation and install another servo. (similar method to the aileron servo... the servo mounts to the hatch) This one... have the whole top of the servo exposed (point the output shaft straight down.) The control horns and pushrods each go on the same side of the servo... (one inboard... one outboard from the fuselage) so one horn will be just a bit further out than the other. Now you don't need a reverser for one servo (yes... it is that simple)

If desired, to regain a bit of the lost roll rate... you can:

A) mix the ailerons to the flaps (but not the flaps to the ailerons)
B) make slightly larger ailerons
C) BOTH!

If you have the channels... you can mix the spoileron function to the ailerons to raise the ailerons when the flaps are lowered. (crow) This needs to be a program mix that can be prevented for normal landings. (it kills speed like all heck)