So it's still one of the better screens I've tried, and it gets a surprising amount of "the basics" right, but starting to notice the flaws -- even though it's alright, my "perfect" 2012 panel is still noticeably better compared to this.
Honestly, I will probably keep it "for now" because it's better to have an OK panel in this laptop instead of the terrible Innolux, and I have actually gotten some work done on here.
What this panel gets right is that I can still read text coherently (unlike a lot of other ones I've tried!)
However, there's definitely times where I get some "mild eyestrain" that I simply don't get on my safe panel. I don't think this is because of PWM or inversion, because my safe panel has those at essentially the same amount.
Fortunately though, no "severe" painful eyestrain like the Innolux! But not a totally pleasant experience either.
Here are the issues I've noticed so far:
I dislike how bright red and blue look with the 100% sRGB gamut. Interestingly, can make these pure colors feel more relaxing with a desaturation preset in NegativeScreen app. But, as white is created by R+G+B together it's harder to change white, definitely white has more "harshness" compared to my safe screen. (This doesn't mean that narrower gamut screens are safe though, as the Innolux was 45% NTSC but it sucked.)
Starting to lean towards glossy instead of matte. Even though matte is theoretically better it seems like no manufacturer can get it right. As I move my head from left to right I notice that the part of the screen farthest away from my head gets slightly blurrier. Sometimes this effect is caused by other screen problems, but in this case I'm pretty sure that it's directly connected to the matte coating. (Fortunately though, there's no matte rainbow or grain)
Weird post-processing thing: Dark wallpaper with some glowing elements + a bright window. When I minimize the window, the glowing wallpaper elements "fade into a brighter version" over a split second. (DPST disabled, PSR disabled, ACE disabled, also tried Basic Display Adapter, still happened. Unsure if this is caused by Windows/GPU or the panel.)
Some kind of LCD overdrive or ghosting is going on, as I can notice colored motion trails even if I disable the green and blue subpixels and only use red. (This is something that to this day, only my safe 2012 panel "gets right", as I don't see colored trails on that one -- it's probably not using overdrive.)
Strangely, the green subpixels seem to be physically better than the red and blue ones. If I set the screen to only use green pixels, I can tell it immediately becomes easier to read or slightly sharper in a good way. (There's definitely something odd about the red subpixels compared to my safe panel.)
The positives: text is surprisingly readable, I still don't get any "immediate" crazy eyestrain (unlike Innolux), and UI proportions generally feel more "correct" compared to other panels I've tried.
However, I don't think I can recommend this one because I'm still getting some strain in Windows 10. (It's definitely a big step up from Innolux though!)
I'm also still optimistic about trying other LG panels especially glossy ones.
P.S. I actually bought two of this same panel, one open-box (this one) and another used. I will be trying the used version in a couple days to see if there is some variation (even between this exact model).
I will also try earlier 2015 Windows 10 versions to check if the OS is a factor.