Yeah, it compiled system files/shaders on every launch. I'm honestly surprised they coded the game to do that instead of storing the shaders after first launch, though I suppose it's to account for newer drivers possibly changing the shader pipeline. I think I ran it off my M.2 drive, loading times to get in-game were around 5 minutes and nearly all of that was shader compile.

I haven't overclocked my CPU or GPU, but I have enabled the XMP equivalent on my RAM. That still only brings it up to 32GB@3200MHz.

Bought and launched through Steam.

And optimizing for PC is HARD. There's countless permutations of hardware. As a developer you can aim for the median configuration, the rig built of all the most common components, but what do you do when that's just not enough oomph to run the game well? Hell, there's variability even among the same components. CPUs of the same model can ramp up to higher or lower boost speeds due to minute imperfections in the silicon. Someone else, who got the same RAM sticks as I did, might find that their system becomes unstable at 3000MHz. As the components get more and more intricate, such tiny faults can have mounting effects on overall performance.