Have you tried the other Direct X bat files? 2070 super should support DX12, which this game uses by default, but see if either DX11 or DX10 works.
I was aware of some GPU hiking issues back when the game first released, but 1.0.8 fixed said issues. At least according for the people who originally flagged them. Sadly, due to the differences in hardware, I can't say for sure what is or isn't the problem.
For me at least, the game climbs to about 15% GPU load and the temperatures stay quite low. A log won't really help if it's a hardware issue, which it might be if it's only on your machine. If you do come up with any theories, though, I'd like to hear them. I don't plan on switching engine so now's the best time to try and squash issues like this so they don't come up in future releases.