The 3x small clutch springs wont help uphill at all, they are meant to increase initial take off from stopped. The big spring, contra/torque spring gets you uphill faster, along with lighter rollers. I use a 1500rpm rated one and 5.1g rollers, get up most hills between 30-40mph depending how steep they are, i only very rarely drop under 30mph but thats only on real steep gradients.
I avoid Kevlar belts as they make a complete mess in the cvt when they begin to fray or sometimes just explode in a ouff of dust and small pieces. They are good for racing etc but need constant checking and last no where near as long as a good quality rubber belt.
A race variator helps with smoothness and speed of acceleration usually, sometimes even gain a couple of mph top end too. Malossi multivar is prob the best imo, but there are others, some are cheaper too.
Sounds like your doing well so far, so carry on
