I just started reading this interesting post and I wanted to share a thought that I had. It was initially stated that these control surfaces are intended for an aerobatic plane. If this includes 3D style flying then a lot of time is spent hanging by the prop and high angle of attack flying where the relative airspeed is close to zero. The only thing that allows you to control the plane in this flight mode is the blast created by the propeller. Obviously this blast is stronger close to the fuselage then at the wingtips (close to zero). Now if it is only the outer 1/3 of the wing tip that is movable then the roll authority of the "ailerons" should be close to zero.

Something to keep in mind if you intend to do 3D. If you intend to do more pattern style flying then this should not be a big issue.

Christian