The downscore reason is that this is not working for me while in private mode. It just sits and spins, but all permissions are turned on for it. Not sure if this is a Firefox limitation that Chrome doesn't have or if there's another setting I can't find, but this is annoying.

This did not work for me. It was just stuck "loading" when clicking the UI button. Maybe I have too many bookmarks, and there is some inefficiency in loading them? I would be happy to test more, if needed.

System:
• Firefox 70.0.1 on Ubuntu.