Arch,
Yeah I hear ya. Just transitioning from a re-pitched 3-blade to an APC 18.1x10 made me notice just how much of an affect different props can have on trim and outside corners. I'm sure with electrics there's even more to deal with (bigger props). Also, I fly with a somewhat more "forward" C.G. so that makes things a bit less critical. I guess I don't notice it as much as some people so I don't use throttle - rudder mixes. Also, I'm not flying Masters yet. Maybe that will make me change my mind.
The only mix I have on my V2.2 is a small amount of rudder -> elevator to trim the knife edge. The plane is fine on uplines and downlines so no throttle -> elevator mix required. I dialed this in with wing incidence and C.G. (which also minimized the pitch coupling in knife-edge). Until I get really good at trimming I just try to watch the plane very carefully and give it what it needs. As long as I get plenty of practice this seems to work.

John Pavlick
Team Black Magic, Tech-Aero Designs