Update: After 6 months of purchase:
I still mostly use my laptop screens only.
Only sometimes I would watch a movie or a few videos on the large monitor, and then get back quickly to the laptop screens again.
I've noticed I have to sit a solid 4-5ft away to minimize the eye irritation effects.
But then that totally removes the immersion advantages and the screen size then is similar to having a laptop much closer to me.
If I sit closer, like arm's length away, then just 15-20m is enough to irritate the eyes.
The interesting thing is that, these "eye irritation, slight burn, itchy eyes, slight blur" effects happen many hours after I finish using it.
Like for instance if I use the monitor for 30m in the evening, I would get the irritated itchy eye effects at 10pm in the night (4 hours later)
Similarly if I watch a movie on the monitor in the night for 2-3 hours and go to sleep, the next day, I'll feel my eyes are a little weaker, get a bit burny and itchy easier.
The effects are not a deal breaker, but compared to having perfectly painless eyes, even the slightest irritation turns me off, and then I do not feel like using the monitor much at all.
There is something that is irritating my eyes related to the backlight I think.
It is not related to motion, because even if I simply keep the static desktop on it, I still get those effects.
Damn! I wish I could find some new tech like an OLED monitor with DC dimming or something in the near future, where I can enjoy a 4k 144hz 32" HDR experience sitting arms length away in immersiveness, and have 0 eye strain. As of now that is just a pipe dream.
Another issue is because of this I am forced to only buy laptops.
Because any desktop would need me to use a monitor, and with an external monitor comes a host of these deal breaker level issues.