Just looked at your pictures, and on the second picture the ailerons can be seen deflected.
My gut feeling, without any scientific evidence, is that the ailerons are too small to give you much roll authority with that big span, I would follow Ollie's advice, or may be even install ailerons on the outboard panels.

Beside that, congrats for a nice looking design, and with that low wing loading, you should have a nice flier, once you get it all straightened out !

Michael

I know it is a lot of work, but I think you would be better off extending the ailerons outward, or adding ailernos on the outboard panels, where they will be most effective. I would keep the flaps in order to be able to use the crow configuration for spot landings.

Aileron differential :
50% aileron differential (then downward aileron deflects half as much as the upward) is a good starting value

Aileron-Rudder Mix :
I used to have that, too, but everybody tells me that it is better not to, that you should use your rudder independently from the ailerons. So now I have set the aileron rudder mix on my planes so that I can switch it off, and am still learning to use my left thumb (I have ailerons and elevator on the right stick, rudder and spoilers on the left), but sometimes, when I am lazy I switch back to the aileron - rudder coupling. On my Alpina I currently have 35% rudder deflection for full aileron deflection, when I use it.

Michael