Just a little heads up, minerstat has the most helpful staff of any Miner OS I have dealt with, they have helped for hours on end making sure everything worked. These guys are great.
Sure, write anytime.

Hello,
1. Can minerstat edit gpu/mem(hbm2) voltage for AMD cards under Windows?
2. Also for Nvidia (fixed like in AfterBurner curve, for e.g. 0.800v for gtx 1070)?
1) You can edit what Afterburner allows to you. on msOS you have more options to undervolt your gpu's.
2) You can set FAN triggers to set fan speed to temperatures.