Giving an update and a little bit more thought on dithering by Intel.
As of now, I am not able to resolve the issue and switching jobs seems inevitable. Currently, I am not using this laptop for work but soon I'll have to switch to it. Which won't be possible with that pain.
About eye patching - I might try it just to see whether it has an effect. It still seems to me that it could mostly help diagnose yourself with a binocular vision issue rather to work like that 8 hrs a day.
New stuff that I tried:
- Connecting through VGA. I used USBC-VGA adapter. Fonts are too degraded and it's not an option. Haven't spent much time testing it for dithering since it doesn't seem to be usable anyway.
- Bought an eGPU setup - Razer Core X enclosure and GeForce GTX 1660s. I am going to keep it since I might need it. eGPUs are a solution if you identified your issue to be a certain video card. It needs Thunderbolt 3 or 4 and connects to the motherboard directly via PCI Express. So, your iGPU and dGPU get completely ignored. It's tricky to set up but it should work. Back to my trial - as I suspected it is not allowed to plug in eGPU because of security reasons. Talked to support and explained my issue and why I need it but they didn't take it seriously and told me to speak to HR. Which I most probably won't do. I can't blame them, they most probably haven't heard such a complaint before and they gave out hundreds of these machines. Or they simply don't care. Anyways, this option is out of the window.
RDP to the machine is done in a finicky way via browser - I am going to try it but I don't think RDP would be suitable for work 8h/day either. Regular RDP is forbidden and projecting your display wirelessly is also forbidden.
There's not much else I can do at this point besides looking for a new job.
I read a little bit more on dithering techniques used by Intel from this whitepaper on Deep Color Support. It seems dithering is done in a more complex way that I originally thought. Yes, the article is from 2015 but it pretty much shows their way of thinking - sacrificing everything else to get the best color at any time.
Take a look at one of diagrams showing what they called "exclusive mode app" back in the day that produces 10-bit (I guess in 2023 we have a lot of apps supporting higher than 8-bit - 10 and even 12-bit):
It seems it works in the following way - an application produces an output (it could be 8, 10, 12 bit) and the GPU driver decides what to do with it based on what OS gives as information about your display.
This practically means if there's an application that supports 10-bit or 12-bit, Intel are going to use dithering if you have an 8-bit monitor (my case). Guess what happens if you spend a ton of money on a true 10-bit monitor and you have application that supports 12-bit - you guessed it - they are going to use dithering on your 10-bit monitor to display 12-bit colors.
This explains why people are affected by Windows updates. This also explains why changing your monitor to a true 10-bit won't work. Changing your monitor to anything specific won't really work. Because this whole process works on a per-app basis - you can have eye strain and headache when using one app and none of that - when using another.
Only way of resolving that is to disable dithering somehow. It seems in theory that even OS could somehow interfere and make all apps produce certain bits to the video driver. Or the video driver itself might have an option to disable dithering. But changing monitors isn't going to resolve issues for all apps.
Honestly, from what I read so far, it seems 99.99% percent of people do not experience issues like we do. And if companies decide to implement solutions for this it won't be because of us. It's not justified to introduce and maintain such an option for so small number of people - everything is money and they would be spending way more than making on us. I hope I am wrong.
I want to thank everybody from this community - it's been really helpful to read some of the threads and get a bunch of ideas. Also, I would be visiting an optometrist soon based on recommendations from the forum.
I might post another update in future.