Once you enable FLPR, you can either set aileron differential (page 15) or leave it at zero. The next step is FLTR (flap trim, page 15). Enable it, then set a percentage. Use a small percentage to start. The manual does not tell you this: if you use 100% you have no aileron control while flaps are deployed.

If you do not want to use flaps but just want to be able to set the ailerons independently, enable FLPR but leave FLTR inhibited or set to 0%. On my old 6XAS the FLTR is inhibited to do this, not sure about the 6EX.