I use iceraven to get around some of these limitations. Addons that I needed(privacy redirect) work great: https://github.com/fork-maintainers/iceraven-browser.

From the github link : The ability to attempt to install a much longer list of add-ons than Mozilla's Fenix version of Firefox accepts. Currently the browser queries this AMO collection Most of them will not work, because they depend on code that Mozilla is still working on writing in android-components, but you may attempt to install them. If you don't see an add-on you want, you can request it.