The maximum cyclic rates are ONLY defined by the aileron and elevator signals comming from the radio. Each Signal (Stick position) has it's own (factory calibrated) rotation rate on its axis.
But what Stick deflection gives what exact rotation rate is depending on the control behaviour setup (parameter menu B), the type of radio/receiver (as they all use different signal ratios) and the programming of atv/travel/dualrate inside of the radio.
But this is only true as long as the physical parameters are allow to have the giuded rate. For example if you guide a rate of 400° per second, but your cyclic range only allows the heli to rotate at 350° then the fbl electonic can not do anything to achive 400°.
Same is for low headspeed, bad blades .....
Always try to give the system as much cyclic room as possible (in "Setup menu L" without binding) make sure to have enought rpm for your fligth style and then adjust the desired rotation rate with the atv/travle or dualrate in your radio.
If you need a fast rotation rate but the system is to aggessive in the middle you are free to use expo as you want, but make sure to set the "control behavoir" ("Parameter Menu B"
to radio before as otherwise you mix up endpoint calculation for expo and expo curves from the microbeast with that one form the radio, this could feel very strange.