As per https://developer.apple.com/documentation/realitykit/construct-an-immersive-environment-for-visionos#Generate-efficient-textures Display P3 is the best color space for visionOS. Display P3 Linear would still require some conversion, but it's significantly less than with rec-2100-linear for instance. This is because it's very close to the final color space. And as a result display-p3-linear has better performance.

Therefore colleagues and I think it's a good idea to add display-p3-linear to CSS, 2D Canvas, etc.