URL: https://live.sfelc.com/events/summit-2020
Browser / Version: Firefox 83.0
Operating System: Mac OS X 10.15
Tested Another Browser: Yes Chrome
Problem type: Site is not usable
Description: Browser unsupported
Steps to Reproduce:
If I change the UA string to Chrome, the site will work within Firefox.
View the screenshot

Browser Configuration
_From webcompat.com with 鉂わ笍_
Thanks for the report.
I was indeed able to reproduce the issue.
Tested with:
Browser / Version: Firefox Nightly 84.0a1 (2020-10-21), Chrome 86.0.4240.111
Operating System: macOS 10.15.6
This is the web page displayed in Firefox Nightly after I access the link:

And this is the web page displayed in Chrome:

Moving the issue to needsdiagnosis.
I asked the sfelc help team why they didn't support Firefox and they replied:
"We didn't see any major issue of Firefox, we just don't have enough time handle the difference between browsers. For example the behavior of choose camera and mic is different. Firefox ask user to decide camera when request permission, so our UI help people change camera will not work."
Thanks for the report @vickychin, and special thanks to @ndkochar for reaching out to them. It's a shame that they don't want to support Firefox, especially since they didn't see any significant issues. 馃槥
There is unfortunately not much we can do here. I'd usually suggest an UA override and an uplift to Beta in this case, but since the event ends Nov 5 and our next beta will be released on Nov 17, that won't do anything for us. We could do an interventions rollout directly to release, but that process involves a lot of people (several of our people, QA, RelMan, ...) and I don't think this case has enough significance for us to go through the process.
Since an intervention is unlikely, and we already tried reaching out, this is - sadly - a "wontfix" from our side. Tagging @karlcow in case he has a different opinion and thinks a release-rollout is a good idea here, just in case.
We could potentially add the override for the future events, but it needs some testing. @vickychin and @ndkochar if you're attending and don't mind joining the event in Firefox with changed UA string (during the days when it's live) it would be helpful. That way you could let us know if the override breaks anything when joining the calls with mic and camera.
Most helpful comment
We could potentially add the override for the future events, but it needs some testing. @vickychin and @ndkochar if you're attending and don't mind joining the event in Firefox with changed UA string (during the days when it's live) it would be helpful. That way you could let us know if the override breaks anything when joining the calls with mic and camera.