This is interesting for sure. So it looks like your Nvidia driver only spiked up to 79, which is excellent (anything under 100 is). The next biggest culprits were ntsokrnl and dxgkrnl which is expected, even on a fresh install without any drivers installed those will spike a little, but they were still good. I'd be happy if I could achieve these results. On XP nothing on the machine ever spiked above 50, but I don't expect these more bloated OSs to ever achieve that again except in niche scenarios, so anything under 200 is probably the best target for most users.
Savitarax also achieved very outstanding results through manual core distribution, but this isn't something we can recommend for the average user as it's too advanced, and also not something we can integrate into an image or automate, so I'd like to strive for an easier solution.
Based on Necrosaro's and Savitarax's posts, it sounds like this is a conflict issue at its root. Something in the OS or the Nvidia driver is taking too long to process and is causing a bottleneck to occur. So by Savitarax manually moving the Nvidia driver to another core it acted as a workaround to solve the problem, because it's removing the bottleneck (we just don't yet know what the bottleneck is). If Necrosaro's tweaks are responsible for his low DPC, then it's highly likely we can eventually have a definitive solution if we find the component removal or tweak that eliminated the conflict.
Necrosaro, if you have a chance in the future, be it days or even weeks from now, would you be able to do a clean install of Windows (without any tweaks) on that same machine, with only the required drivers installed and check the LatencyMon results? This would greatly help to rule out a lot of stuff. For example, if a clean install has bad DPC on your machine then we know right away that the solution lies within your tweaks, but if a clean install results in equally good DPC then we can ignore all the NTLite and post-install tweaks and focus on hardware and bios instead as that is going to be where the solution is.
I followed the link AeonX posted and in one of the replies a guy asked how the OP achieved such low DPC, to which the guy responded with 3 more links. I checked those links out briefly and there was actually a lot of good information in them, surprisingly. I already do a lot of their tips, but I'm definitely going to add those links to my todo list and work my way through all of them to see what else I can come up with that helps. Everyone should be wary of that LatencyMon screenshot posted on that forum showing stupidly low DPC though, because it was only a 10 second snapshot which is easily fudged and meaningless.