Hi there.
I also bought a RTX 3080 for my P775TM1-G with the new Heastsink from Aliexpress. Gsync still dont work. Today i made the shunt mod also like @incendery to 180w. The USV also shows around 30w more than stock. @Kungfumaster21 sorry i know your problem i had the same but i didnt wrote it down. Start wirth the smallest and try it a few times until you see everywhere a imprint.
My 3D Mark Results:
Stock : https://www.3dmark.com/3dm/121052151
Shunt Mod: https://www.3dmark.com/3dm/124272582
Shunt Mod + OC : https://www.3dmark.com/3dm/124281731