I would like to be able to whitelist certain domains for 3rd-party device recognition, regardless of the 1st-party domain it appears on, instead of whitelisting all 3rd-party domains on a particular 1st-party domain.
I work for Sketchfab, which allows you to embed a 3D model viewer iframe in other websites. The viewer relies on device recognition to detect WebGL, which is required for the viewer to function. I visit many, many websites that have Sketchfab embeds in them, so I have to allow all device recognition on many domains. I would prefer to globally whitelist sketchfab.com for 3rd-party device recognition and continue blocking any other 3rd-party device recognition that may be happening on these other arbitrary websites.