Supports loots of addons
https://addons.mozilla.org/de/firefox/collections/17446767/Fenix-Addons/
I think later this month a version will be launched that will enable practically all the desktop extensions…
Pre-enable. I dont think they will change how the addons work. The Browser simply has a different preset addon collection of addons available.
See my collection, I tested all these and they work on mobile. Lots of features like Tabs, popups, advanced Downloads etc. dont work, but other things do.