You are probably already aware, but there is an official extension that offers this functionality via sand-boxed tabs: https://addons.mozilla.org/en-US/firefox/

You are probably already aware, but there is an official extension that offers this functionality via sand-boxed tabs: https://addons.mozilla.org/en-US/firefox/addon/multi-account-containers/ https://addons.mozilla.org/en-US/firefox/addon/multi-account...