Rich, glad you found the right prop!

Can't say for sure how the wing incidence modification will affect KE performance, but suffice it to say that the vast majority of planes - including exquisitely trimmed, megabucks pattern planes - usually have a bit of elevator and aileron coupling in KE flight.

I forget exactly how much and what direction, but my Phx extra, with the wing mod, still needs a bit of elevator and aileron to keep it going dead straight in KE, but it is so little that I haven't even done a mix for it. You can do a rud-to-elev mix (and rud-to-ail) mix and get most any plane to do a "no-right-hand" KE in dead calm conditions, but even then if there is a little wind you will still have to do a little correction. Also, left rudder KE and right rudder KE will almost always require a different mix, and it may also vary with throttle setting (airspeed), so sometimes it is best just to fly with sticks, and the plane will tell you what it needs.

I had an interesting experience late last season when another member of my local club wanted me to do KE mixes for a .60-sized P-51. With the low wing and high dihedral I figured the ailerons would require a ton of mix, but the elevator required a humongous amount of correction, so we started out with a simple rud-elev linear mix and I think we ended up with about 35-40% elevator-up mix - HUGE. Funny thing was, after doing that, we were shocked to discover it needed NO aileron mix, and it would do perfectly straight, no-right-hand KE's with left or right rudder at anything from mid-throttle on up. Quite amazing, actually!