ORIGINAL: vh2q
I appreciate the insight and it does make sense, but I am not sure what this means:
I would suggest trying to increase the dihedral or adding ailerons (regular or independent spoilers), in order to increase the roll stability or control.
It will good to verify wing wraps and symmetry and lateral balance, as well as taping the hinges' lines
Sorry, it is my poor English..........
Additional ailerons can be regular (requires modification of the wing's structure), or added to the top or bottom of the trailing edge (I believe that the proper name is split aileron). In the case of split ailerons on the bottom surface, they create undesireable adverse yaw.
Some full scale airplanes use spoilers functioning as ailerons, which rise up at the top surface of the wing independently one from another. If the spoiler of the right wing i srised up, the lift is spoiled and the right wing falls, initiating a right roll for banking and turning.
Regarding the hinges: it is good practice to cover the gaps with flexible tape or plastic cover. This avoids air leakeage from the high pressure side (the one towards the control surface is deflected) into the low pressure side. This increases the effect and finese of the controls. In your case, the hinge lines of the elevator and rudder are the ones recommended to be covered.
Regarding the dihedral: it may be possible bending the wing tubes upwards a little to gain some degrees of additional dihedral.
Regarding wings wraps: it was a typo, I meant to write warps or twisting along the span. Sorry.
Regards!