At long last Windows appears to be rebuilding their color management system including handling wide gamut displays. As of the new build of Win 11, this is supposed to be happening:
Both my wide-gamut XPS dells (one new) are running the new Win build; neither has the option that article mentions.
In my cynical old age view I'm not expecting much out this alleged new feature, but if any of you actually get it to work (as intended!) on a wide-gamut display, let me know.
Unfortunately, one thing that has changed with the new build is DWM_LUT is now broken (an awesome tool that lets you apply a 3D Lut to your Windows desktop, so you can take color management out of Window's hands entirely). I don't know if the developer will be able to get that working again.
For now, if you're using Vegas Pro on an unclamped wide-gamut display, your best bet is probably to create a high-quality 3DLUT using DisplayCal (assuming that's not broken also), disable color management in Windows, and just add the LUT to your preview fx for editing, remembering to disable the fx before you render. Maybe someday Vegas will allow us to add a Preview LUT like Resolve does for Display calibration only?
As for the future, hope for a DWM_LUT update, and I guess we can always hope that Windows effort to improve its color management system pans out (insert cackling laughter)