Kryonaut is not the best solution as it pumps out easily above 80C and you end up with worse temps after time.
For me the best solution is Phobya Nanogrease Extreme
…and as far as I know, the Full HD panel on KM-G is either 144Hz or 240Hz or 300Hz…
so there is little chance the G-Sync will work unless your 144Hz is exactly the same model as the one on default for KM-G
For G-Sync to work, the panel subtype should be included in the cookies responsible for the combo GPU=>Panel in the system BIOS. If SM-G and KM-G shared 100% the same 144hz panel, then the G-Sync would work.
Any other subtype (the last two digits of the panel) except for the existing 144Hz one for KM-G - you are gonna lose the G-Sync on the internal display.