I bought my 12 from original owner with 48TT. The airplane had a small trim tab fastened to the left flaperon with double-sided tape. It worked but the trim tab looked obnoxious and tape isn?t exactly structural. I removed the trim tab and the plane flew with a very heavy right wing.
I checked and adjusted the straightness of the upper wing skin that trails behind the spar and also squeezed the trailing edge of the flaperons. Neither solution fixed the problem.
What I did find extremely effective was changing the height of the flaperon pivots. Its been several years now, so I can?t remember exact adjustments, but basically what you want to do is raise flaperon pivot on one wing and lower pivot on the other wing. Perhaps start with ? turn up on right wing and ? turn down on left wing and test fly. Again, I can?t remember which flaperon I raised and lowered. No big thing ? just note the change and test fly. First test flight will tell you if you?re adjusting in correct direction. If wing is heavier in flight then do opposite correction.
I believe I ended up changing pivot heights by one turn of the rod ends. One wing one-turn up and the other wing one-turn down. Plane now flies hands-off and ball is centered in cruise flight. Deploying flaps anywhere in the white arc is still hands-off level flight.