seems like latest s2 firmware allows undervolting im running at 0700 instead of the 0725 that it was running at we shall see how this runs for a while till somebody eather wants to trade it or buy my setup i still need to figure out a good price and still need to figure out escrow never used it before or know how to use it
No, you can't undervolt with the firmware you need to modify the resistance by taking it apart.
Its alot of work but for some, its worth it. Makes the miner quiet and more efficient and won't kill the PSU.