This falls in the large basket known as "unintended consequences of alterations to a perfectly good design"
My aircraft is a highly modified EAB "sorta RV-12" homebuilt.Most of the 100 or so mods I made have worked out well, and I had great fun making them and proving them out.
One of my mods was an aileron trim system, in which I embedded a tiny (two oz) linear actuator from the RC model world into my right flaperon, and used it to drive a trim tab which is a 2"x 8" hinged tab mounted on the trailing edge of the flaperon. Works great, and I get a kick out of watching the Garmin G3x system auto-trim the aircraft in cruise at any speed!
What I missed is the fact that a trailing edge tab will act as an anti-servo tab when the flaperons are deflected. In fact, it induces a noticeable roll to the right that does not go away as long as the flaperons are deflected. (-obviously, since the tab will exert a force to raise the right flaperon just a smidgen - which produces a significant and residual roll to the right!)
Solution: Install an identical, but fixed tab on the other side. Now the tabs cancel each other out when you deploy "flaps" and you go down final hands-off!
Test flew this today