Dadab12
I forgot to mention I have more eyestrain when running my 7i at 60hz so I leave it at 240hz. Mine defaults to 240hz out of the box. It should be the same with your newer version. If you could give me the full specs of your purchase, maybe I can confirm some things.
Edit: also I installed the version 532.10 nvidia studio driver for the rtx gpu not the game ready driver. No particular reason I installed version 532.10 as I'm still exploring older driver versions for potential solutions to reduce eyestrain.
If the 7i (whichever model) does not work out, in this discussion I have also tested my T480s (bought ebay used for around $200-$300). I run linux mint 21.3 with it now and tested windows 1809 enterprise LTSC on it as well and both feel relatively comfortable. I swapped the LG screen panel it came with for the AUO panel because of my microscope testing. The AUO panel seemed to have less pixel flicker. The T480s I have does not have discrete gpu so no gaming. Their is another version of the T480s with nvidia mx150 discrete gpu. I don't know if the mx150 has temporal dithering issues. In any version, it's a work laptop.
The forum member DisplaysShouldNotBeTVs mentioned the 2012 Lenovo IdeaPad Yoga with Win8.1 as safe here:
https://ledstrain.org/d/2686-i-disabled-dithering-on-apple-silicon-introducing-stillcolor-macos-m1m2m3/521
I use an external thinkpad keyboard first because the laptop is placed on a stand away from me and to raise the monitor to eye level forcing me not to have too bad posture. Second reason is less potential "EMF" (basically electrical interference with your body, sounds weird right?) but that is a tricky and controversial topic even more so than LED flickering.