Greetings from Sunny Queensland.

What percentage of flap to elevator coupling do you use on your fun fly models for radical flying?

Is the flap throw 50% of elevator throw?
Is the flap throw 75% of elevator throw?
Are your flaps depressed 30 degrees when the elevators are raised 45 degrees?

Is this just a trial and error thing with every model set up differently?

I find that my models will not do a flat spin when the elevator and flaps are coupled. I can do great flat spins with the coupling switched out. (I have yet to do a climbing flat spin.)