Provide (helpful) mechanism for users reporting site breakge
Websites break in Tor Browser. Sometimes the "breakage" is in the website's functionality, sometimes it is how the website is rendered, sometimes the website blocks connections from the Tor network. Each of these problems is a usability problem. The first two categories include breakage we can investigate and (possibly) fix in Tor Browser if we have enough information. The third category is an advocacy problem, and it requires different solutions.
Firefox includes a reporting flow in the Tracking Protection UI: https://support.mozilla.org/en-US/kb/report-breakage-due-blocking https://bugzilla.mozilla.org/show_bug.cgi?id=1474238#c18
Or, we could roll our own, but I don't see much benefit in spending time doing that.
The most significant concern is how we limit reports such that we're not overwhelmed by garbage and we waste time looking for the needle-in-a-haystack.
For completeness, I'll make a note about the site breakage reports Mozilla received already regarding only enabling resistFingerprinting in Firefox (not including enhancements introduced in Tor Browser): https://bugzilla.mozilla.org/show_bug.cgi?id=1507517