I think the only thing that's missing is allowing the containers to sync with Firefox Sync with a client-side passphrase. I don't want to lose all of that "work

I think the only thing that's missing is allowing the containers to sync with Firefox Sync with a client-side passphrase. I don't want to lose all of that "work" I've put into carefully separating websites into their own containers when I switch to another machine or re-install the OS, etc. Also, it should be easy to "reset and switch" a website from one container into another while leaving no traces that it's been in another container. I often load a website in no container or in another container, and then I use another plugin to switched it to where it should be. This should be a default feature.