Don't use Dual rates,, just learn to use the stick more precisely
Don't use Expo,, same as above
Don't use servo reversing, learn to set the plane up.
Don't use Sub-trim, same as above
etc.
etc.

All "crutches" right? I flew without those crutches for years too

Funny how you guy say "fly a Heli to hone rudder skills",, Apply this "don't use mixing" purest theory to helicopters,, and don't use a Gyro learn to use the rudder and you'd have a uncontrollable eggbeater crashing constantly,, "Cricket" anyone??

See these features on the radio make the flying experience more enjoyable and when used correctly make for a better flying more finely tuned machine, they don't replace flying or learning how,, they just make it better.

Disconnect the power steering and power brakes from your car and see how enjoyable that experience used to be,,