I did some research and for me problem is in video driver. Try to use windows 11 clean installation without actual drivers installed, especially without video driver, use default from Microsoft, in my case I do not get any symptoms. Same for linux, there are possibility to block loading kernel modules with driver and use default lib, with this there are also no issues, in general linux more tolerable for me then windows, even with normal video driver.
Regarding apple and android phones, they also use video drivers to which you do not have any access, so we having issue with phone. I noticed that I ca tolerate iOS till 15 version, starting from 16 version I getting issues. The same is for Mac OS, last usable was Big Sur for me on intel Mac Pro 14, after upgrade to Monterey latest supported, it’s not usable for me.
So I think problem is not in pwm or screen, problem in video driver, some setting added and set as default an give us issue, the only thing no one knows what is added))) Also I do not think that temporal dithering is issue as well, because I can use fro example monitor with 6bits +frc without issue if if connected to device which is not give me issue, if connected to bad device it gives issue as well