PIC of da grease
Used just enough to cover the base and a bit of the lip of the f1, spread it with a ruler
Pot was very stable, within 5c of the bios from 20c to -80c before the first pull
Chilled down to -140c, pot was still easy to twist and easy to pull right up didnt have to force it. Pic is me pulling it up and booting to get around the CBB. Worked great, little ice around the socket because I wasnt using any paper towels or the usual black neoprene insert.
And a pic after playing around for an hour and a half with pot around -170 the whole time. Dielectric really kept the frost at bay
In conclusion. I would use a bit more of the grease next time. After pulling 2 or 3 times temps where poor. -80c in bios with a full pot. Holding the pot down with some pressure for a minute helped by melting a bit of the ice on the edges then freezing back up in place. All and all worked right to plan, let me play with the board around getting used to aux voltages the chip likes.

I will use this method again for sure.
http://valid.canardpc.com/show_oc.php?id=1244534
at -80c with plenty more voltage to go. Might be a winner.
The board on the other hand is very quirky, will have to start a new thread for that.