Easy. Use a cubic function. I use a cubic function no matter how sensitive my drive train is. Basically it lets me get very fine control when I move the sticks lightly but if I move them all the forward I can get the full power. I would give you the exact cubic funtion i use on desks but I’m on mobile rn so lol can’t do that. But here’s a pic anyways
See how it starts out slow but exponentially increases? Tweak around with some of the vars until it sits close enough to (0,0) and (127,127) and until you get your desired curve. Then just use your motors as y and your vexRT as x.