Do keep in mind that the separate aileron installation is going to be heavier (up to twice when using solid trailing edges) than the conventional aileron installation. What you are doing is duplicating the trailing edge structure twice (kinda) (always use weasel words if necessary).

Loss of effeciveness with an aileron that was reasonablely sized to start with can always be made up by a slight increase in deflection or just holding in a deflection for a longer time. Most airplanes, expecially man carrying ones, fly upright, level, for long periods of time. The deflection of an aileron is a rare occurance and for just a few degrees at a time. In that respect a conventional integrated aileron is just as good.

It is difficult to sing the praises of the McCessna installation unless you have models with and without that aileron installation. Then a reasonable statement can be made as to the gains or losses of that design.

It is interesting that in a design where the airplane's good aileron response is really a prime factor, namely the aerobatic airplanes, that the conventional aileron is always chosen.

In all of the airplanes I have worked on in which flap aerodynamic effectiveness was given prime importance and structure had to produce the design regardless of difficulty the conventional double to triple slatted flap was always chosen, not the Junkers type of flap.

In initial design of an airplane you have to look at what is most important for your particular use and see if the trade offs are worth it.