Listen, HDR support is lacking on any system, even on Windows where Nvidia puts most their efforts on driver support.

HDR calibration in Windows results in really washed out colors.

And HDR quality in viedo games varies immensely from title to title, everything from an on/off button to visible image calibration.

And at any rate HDR should be controlled on video card driver level, like it is for SDR (at least with Nvidia).

HDR is to me a necessary technology that has become a permanent afterthought.