Would appreciate any comments or feedback on the spec.
Edge bug: https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/12189241/
Blink Intent to Ship for newest parts of the API: https://groups.google.com/a/chromium.org/d/msg/blink-dev/UVfNMH50aaQ/4Hy5h-wzEQAJ
Forgive my not closely following the development of this spec. Has there been any discussion on the fingerprinting impact of exposing this additional information about the client? I've read the compelling use cases, but I'm quite concerned about the privacy of our users. This might not seem to reveal anything too sensitive, but it adds significantly to the reliability of tracking people who might not want to be tracked.
Yes, definitely a topic that's been discussed and brought up on many occasions. The privacy section in the spec  should, I believe, cover the up-to-date state on where we've landed so far. As related reading, both of the blink i2s's are worth reviewing [2,3].