Ended up going fine. Worth noting that I did not need to go to the Windows Store to get the Nvidia Control Panel... it just automatically triggered an installer for it that was presumably bundled directly with the driver, the first time I clicked on the Nvidia Control Panel icon after doing the...
Is anything weird likely to happen if I just use the installer in "Express" mode the same way I did for the non-DCH version, while coming directly from a non-DCH version?
Yeah, I still haven't quite found the best combination of core / uncore multipliers quite yet I don't think.
Also, @DR4G00N, 2055MHz / CL7 is nuts for first-gen Core! Really nice results.
Very glad I did not listen to the people who said "just buy the cheapest kit of DDR3-1600" back in 2013. Early last year I swapped out the GTX 780 the PC featured below originally had for a GTX 1660 Ti, and I'm fairly confident I'd be getting much worse results with it if I did have something...