[AlbinoDrought]

Needs a workaround, but you should be able to install a limited amount of any extensions using the "Custom Add-on Collection" option: https://web.archive.org/web/20211007060220/https://blog.mozi...

I've used this to install one of the otherwise-unsupported *Monkey Userscript extensions

[nathcd]

Looks like that's only on Nightly? I'm glad there's a workaround, but I'm not missing Redirector quite that much.