I like the idea. Third voice was fun for a while.

Are the iframes opt-in per domain? If not, how do you deal with leaking internal DNS names (referers) from within companies and government organizations? I don't see a referer policy [1]

Does your addon respect CSP policies? I assume the browser would enforce this, if iframes are not permitted.

[1] - https://securityheaders.com/?q=https%3A%2F%2Fcomntr.github.i...

The domain mentioned in the README is not up.