the throttle closed will have no effect on the T-tail. Hence you cant do wheelies for grass field takeoffs.
correct the prop wash negates nearly everything in normal flight conditions.
I don't think the blanking has that much to do with it if your demonstrating yaw maybe a good boot full but not a squeeze for a demo.
Personally I think we can discuss the dynamics of it all. But it will all come down to that bloody awful trim system.
Need to get someone to try it in a seminol to see if its just a vice of the tommy.