Cool, last time I used Firefox on Android they only supported extensions on Desktop. I'm glad to hear progress continues!

I believe you have to install "Firefox Nightly" from the playstore to be able to use extensions like uBlock on mobile.

That's not accurate. For a couple years, Firefox limited extensions to a very short approved list, but even then, uBlock Origin was on that list.

That restriction has since been removed, however installing from local storage is limited to nightly.