Guys are using fuel tubing split down the center and sticking it on the TE of the rudder.You can also take coroplast {its vinyl cardboard} and cut a section of it to put on the TE. Just cut it so you have a piece that is a 90 degree.Make sure the section of the 90 in the airflow is only 1/16 of an inch wide. The coroplast is harder to do but you can get a color to match your plane.I think it looks a lot better than fuel tubing. The reason the FC hunts on the rudder is because the TE is so sharp.All you need is something to break up the airflow slightly. The airframe is very light for sure.I doubt you will notice much diffrence in the vertical speed.All the FC plane's I've flown seem to have a very constant speed all the time. Jason D.