Most Edges, Caps, and Extras exhibit some pitch coupling in knife edge flight. With both the W/H 28% Edge and Extra I think you will find that about a 4% elevator to rudder mix in right to left, canopy to you K/E will eliminate the coupling. In left to right the percentage will be a little bit more or less. Sorry I can't remember which way and how much. Have a friend at the flying field take some notes for you before you perform any mixes to note which direction couple the most and to which direction. Try to just roll the plane on edge and use the rudder only without any elevator or aileron to make a true determination. Use a power setting that will let the plane hold altitude relatively well. Do one mix a little bit at a time, landing between test flights to make the changes. It can get a bit dangerous trying to push + and - buttons in the attepmt to make the changes in flight.

Your next mixes will be in a vertical upline at full power to see if there is any up/down or side to side pitch changes. That will be a throttle to rudder or throttle to elevator mix, perhaps a little of both. The reverse will be true for the vertical downline at low power settings.

Trimming a plane for excellent flight in most, if not all, flight attitudes is the name of the game and will make you look to be a much better flyer than most people at the field. It's a slow process and will take many, many flights. The location of the c/g is part of the trimming equation and should be the first change you make before you add any mixes. I had forgot to add in the first paragraph that pitch coupling in knife edge will often be affected either positively or negatively by the c/g location. Move it back to about 5-1/4 to 5-1/2" if you're not already there and see what the effects are. Then start the mixing-trimming process and fly well