ORIGINAL: highside
OK, sorry for the confusion.
The feature I require is to adjust the Rudder Rate (or AFR, travel, sensitivity or other loosely equivalent term) as a function of the throttle position. Ideally this needs to be via a curve rather than being constrained to be linear. For F3A, the use is to progressively reduce the rudder travel as the throttle is opened. It takes a bit of setting up to get it right but it really makes a difference in integrated rolling manouvres and rolling circles, especially when it is blowing a gale and upwind and downwind airspeeds are significantly different. As a an additional advantage it can be used to give full rudder travel at idle for stall turns and spins - I know some people use a switch for this.
On the 9Z, you can do this using the Rate Control programmable mix (CTL), p.66 of the manual. From memory this provides a five point curve for the feature (might be 7).
I'm not familiar with the other Z's and the 14MZ and 18MZ, but I know other pilots doing it on the MZ's. The manuals for these do not mention a CTL mix type, but I assume there is another method - possibly the VTR mix type, but it is hard to tell from the manuals. As for JR/Jeti/Hitec/Spektrum/Airtronic I also can't find anything obvious in the manuals, hence the question
HS
I can confirm that with 12Z you can control the mix (say to rudder by throttle) through a multi-point curve. The curve can be potentially discrete: at low or middle throttle range, almost no mix, and at/after a certain point, 2% mix etc.
On 12Z, multi-point curve is just one type of mixes. Others include exponential, linear etc.