Provide input or mitigate W3C Proposal for css-mediaqueries
TBB Team may want to be proactive on an upcoming W3C Proposal for css-mediaqueries as it is already at Level 5 consideration.
New HTTP Header (Fingerprinting Risk) - https://github.com/w3c/csswg-drafts/issues/4162
System-wide dark mode setting to automatically toggle based on location-dependent data. https://github.com/w3c/csswg-drafts/issues/4404
"If implemented naively without taking privacy into account, such a feature combined with prefers-color-scheme could potentially reveal the user's longitude to all websites with a remarkable degree of precision. (Multiple readings over the course of a year might also be able to determine latitude to some extent.)"
Overall this seems like a very bad spec as currently written, and could just as easily be done with current JS rather than forcing time-based tracking into headers and CSS code in all major useragents.