How does Windows map SDR to HDR? or does it use the reserved bits of the rec2020 colorspace to embed dci-p3/srgb/adobergb/rec.709 pixels?
Do I need to use displaycal to build an icc profile for each colorspace? I’d expect it would be possible to do computationally.
Backstory:
Yesterday, I just got an Asus PA329C that has a true 10bit 4k panel and is Display HDR 600 certified.
I enabled HDR and tuned SDR brightness down from windows default of 50% all the way to a more reasonable 25%.
Hurray !! HDR works and everything looks amazing, I now wish everything was using rec.2020.
I then noticed my display, for SDR contents looks slightly more Nikon/less Canon 
- SDR needs more pink, HDR on the other hand looks fine.
I keep reading how Asus calibration software is junk, and it supposedly came calibrated from the factory so I haven’t calibrated anything yet. Should I try the Asus calibration?