simplex
I used Windows 10 22H2 19045.5371, with updates up to January 2015. However, I think switching to 6-bit mode will also work in Windows 11.
But, speaking about my BenQ GL2450 (6bit+FRC) monitor, I can use it comfortably only on macOS with an Apple Silicon M1 graphics card in 8-bit mode; 6-bit on Intel is less comfortable.
However, on my relatives' monitor, the BenQ BL2420PT (6bit+FRC, with flickering), the most comfortable setup is Intel UHD 48EUs in 6-bit mode on the aforementioned version of Windows 10; macOS on Apple Silicon M1 is much less comfortable.
I would recommend experimenting to find what works best for your eyes.
P.S. I also noticed an interesting thing: there is a difference in eye comfort between 60Hz and 59.94Hz on my TV. For some reason, 59.94Hz feels better. I assume this depends on the display and won't work everywhere, but if you see 59.94Hz in the list of available resolutions, try selecting it and see if it feels better. On both Linux and Windows, when connected to my TV, I have both options available. Tested on two different PCs with Intel and AMD graphics cards.