Are you a developer? If not then the only thing you need to know is that Mozilla is essentially announcing enabling desktop extensions to be able to work on mobile
It’s an extension that allows you to blacklist certain websites from appearing in search results. So if you wanna prevent for instance facebook links from showing up in search results, uBlacklist can make that possible.
I’ve used Firefox Nightly for ages, and admittedly, it sometimes lets a crashing bug through. But it was worth it for stuff like old.reddit redirect on tablet, lol. I just don’t want the stupid “USE OUR APP” notifications while searching.