Colby,
If I can get the mixes figured out on my 9C and have enough left I am going to try to couple flapperons to the rudder.
It may be awhile.
I am still trying to work my way thru some of the other stuff.
It's all so new since I've been away from it for over 15 years.
You are right about how severe it is.
Today I put the rudder to it in knife edge and made a conscious effort NOT to correct any coupling.
I think you could just about do a knife edge circle with it and not put any elevator input!
It does so many other things so well it's a shame it's got this one trait.
Oh well...
I guess that's what the computer radios are for!

JLK