Wasn’t this the blog who also got a response from session asking for a PoC and then they replied with (paraphrasing) “well it’s not my job to provide one”?

So everything in that blog post is theoretical at best?

The colour management protocol on wayland got merged yesterday, and KWin has already switched to the now complete spec.

GNOME are surfacing HDR in GNOME 48.

With WINE’s wayland driver having a year of fixes, hopefully Valve will use it in Proton 10 allowing use of HDR in games running via proton.

I wouldn’t call it solved just yet, but it’s very close.