I'm already on it as might be seen here.
Feel free to complain loud and clear if it doesn't work in FF. Make it clear that FF support isn't optional.
Also on my to do list: complain even more, including to relevant authorities about Googles abuse of market position to push their browser. Feel free to join me here as well.
(And to be sure: feel free to complain when supposedly mainstream sites doesn't work in any major browser - safari, edge, FF and even Chrome : )
In the meantime, FF support (while, for now, relatively inexpensive/free if you just use web standards) will just continue being optional considering Chromium's quasi-monopoly.
Only once have I experienced that something I'd actually write for production only worked in FF and not across all modern browsers.
Protip for anyone who reads this and thinks "but my employer doesn't care about Firefox':
I typically used FF also while testing other peoples work and if it didn't work in Firefox then 9 out of 10 times it didn't work in any other browser than Chrome (had some devs on my team who really didn't seem to care about cross browser compability but it would work in most browsers before it was approved :-))
Suckiness of the browser situation aside, I fear I'll soon be coming to miss those days.