I had the same concern, I have read that people who have set it up per instructions aren't having any major problems with it. but peaople who want it to work properly have been changeing the aieleron linkage setup as follows

by extending the control horn from the edge of the aileron as opposed to installing them on the aileron surface you can get the proper deflection.

I have don mine as the manual suggested and CA'd them in place, so I don't want to tear the wings up getting them off. I will try it like this and if I have fun it will stay. If it sucks then I'll cut the horns off and leave the brackets, get some new 1mm wire and slot the aileron edge and glue the horns in the new way and make new linkage. on another forum they have some really good pics of the setup. Sorry for the lousy graphic,