Forks are pretty valuable to Firefox development, and it's helpful for Firefox marketshare too because they use the same UA as Firefox, so website must support Firefox.

Even Firefox devs said they observe Firefox forks to see their idea and bring back to Firefox, just compare recent new features of Firefox to Zen/Floorp, you would see that the idea of:

• Profile Manager is from Zen/Floorp
• Vertical Tab is from Zen/Floorp
• Sidebar is from Zen/Floorp

And many small things.

Can this poll be considered official ? I clicked the link and it looks like a Twitter poll or something.

Yep, waiting for this feature so userChrome.js cook-ers can turn it into Tree Style Tab Group like Sidebery, with this config exposed it would be surprised if it takes long for us users to try the test version.

Smart Tab Group is pretty hype too.

There's many users who would kill to have this feature from Arc, just let you know. It's innovative, that's why it should be an option for people who want it, it needs to be polished though, like not popping on no audio videos and a soft-whitelist.

Because of the fact that UltimaDark is going the hardest route, using a totally different API, unlike Dark Reader

Yep, people have benchmarked:

• Firefox without any Dark Mode addon = 27 points Speedometer
• With Dark Reader = about 11 points
• With UltimaDark = 25-26 points

It does, enable Desktop Mode and install