I apologize if this has alredy been done to death, but let me see if I have it right...

Dual rates are two different throw rates for the same plane/rx/servos/tx, set at the tx?

Exponential... I understand the term and the implication. My question is whether this is for digital radios only? Dual rates take a digital as well?

Are these setups widely used?

I must admit that I haven't done a search. But I've been here a while and haven't seen any posts on this subject.