For Knife edge flight or point/slow rolls, coupling is easy to deal with because you're not using much rudder throw. So a little computer mixing can really take care of a plane which pulls to the canopy or gear in knife edge. When you start doing KNE loops and lollipops, which use more throw, my experience has been that the coupling increases or even changes how it is manifested as you approach full throw. So the same mix you used for pattern maneuvers might not do it. My radio (9C) is supposed to have exponential mixing curves to aide in this, but I haven't tried them yet. For now, on my Goldberg Extreme, when I do a tight KNE loop, I just have to add a bit of alieron.