Hi Blueberry,
Cheers - yea I saw they were looking into it on Reddit, but figured would add another video/dxdiag to see if it would help with diagnostics or narrowing things down. The most recent step I did was a BIOS update and minor overclock which seems to have stabilised the cpu graph at least and improved it a small bit. ToW this week was a lost cause however, so looks like i'll be buying the Boys Rifle!
Cheers for the support - hopefully root cause is found as I know it doesn't effect everyone. I'd disabled DXR alright, may revert back to DX11 again. (although it had improved a bit)