Don't know of anyone using a flap sensor on a Kitfox for AOA. Most of us Kitfoxers with AOA calibrate it in the landing configuration (1/2 flaps is fairly common) and leave it at that. No flaps or full flaps only changes things by about +or- 2 mph. If the AFS system has the ability to adjust AOA settings for more than one flap setting that is cool. If you really want a flap sensor I would think mounting a couple of microswitches under the console to sense flap lever position would do the job.