[andrewaylett]

Other people have already answered your actual question, so I'll weigh in on my assumptions of your use case instead :).

I find that multi-account containers give me much of what I would otherwise gain from running in multiple profiles, in as much as cache, cookies and other state are separate, so I can be logged in to a different set of accounts in each container. Temporary Containers makes life ever easier -- a whole new empty state at the push of a button, and parallel non-shared state: it's much more usable than Incognito for web development and testing.

On the other hand, if you want a different set of extensions then multi-profile is the only way to go.

https://addons.mozilla.org/en-GB/firefox/addon/multi-account... https://addons.mozilla.org/en-GB/firefox/addon/temporary-con...