>>105694459programs should not need to add the feature in if your card's driver supports DRI/DRM as Xorg can technically pass 10-bit pixels already, it just can't decode them for compositing and stacking purposes, which is why it's "technically" possible to hack HDR10 on Xorg if you're bypassing the compositor and overwriting the full framebuffer, unfortunately "HDR on most consumer displays doesn't actually use 10bpp colors, they commonly uses 8bpp + 2 extra bits to vary brightness as a cheaper to implement option.
the downside of the above is that all 8bpp applications will be unable to display correctly as there is no function in Xorg to convert 8bpp to 10bpp
I think the above is part of why xnamespaces is being developed since you may be able to detect an application that wants to draw 10bpp vs another that wants 8bpp and isolate them, and do some sort of color-conversion similar to what nvidia got blocked from implementing in Xorg back in in 2017