I checked the original thermal pad, they're 1mm thick. It should be possible to replace the thermal pad with thermal paste if the paste is thick enough to cool the VRM.
The reason I'm doing it is that I'm going to do the shunt mod on FTW3 1080Tis because the power limit bug is a joke to 1080Ti family like ASUS Poseidon (Every benchmark on 2K and above, FTW3 lost shamelessly compared to Poseidon and OCed FE cards)
And the FTW3 maybe need a better cooling on VRM or VRAM if the shunt mod is done.
 
The potential thermal paste on VRAM: Thermal Grizzly Kryonaut 12,5 W/mk (silicone-based nonconductive) or Thermal Grizzly Hydronaut 11,8 W/mk (completely nonconductive)
Some good thermal pad on VRAM: Fujipoly or Thermal Grizzly Minus pad 8.0 W/mK 
 
The system power supply is EVGA 1600T2, so it should be enough. I just bought it last week because the original Seasonic X-1050 is on its full capacity during the 4K benchmark and even gaming like The Rise of the Tomb Raider. The system shuts down due to insufficient power.
 

Thermal paste isn’t going to have the contact you want. It may flow when it heats up and move off of the vrm and vram, which will do you no good at all.

Use the thermal pads, they are there for a reason. Gamersnexus already did the tests to show that the stock thermal pads are more than sufficient. If you want to use the fujiploy, they will definitely work well.

x3
Don't use thermal paste.

The cheap stock pads do an adequate job. But, if for some reason you want better, buy some fujipoly thermal pads. 11 W/mK versus 1 W/mK. The only problem with fujipoly pads is that they can rarely be reused each time you take the heatsink off versus the stock pads which can often be reused.

Thermal paste on VRM & VRAM?!?! Uh, no. Not a good idea at all. No need to do the shunt mod either. You can just load this vbios to your card.

No I don't believe the voltage can be turned down on the xoc vbios.