Learned something new, thanks. This doesn't look terribly user friendly https://support.mozilla.org/en-US/kb/profile-manager-create-.... Edit: And in testing I can't have multiple profiles open at the same time.

You can also use about:profiles, which is a little nicer than the profile manager.

So that seems broken as well, when you click "Launch profile in new browser" it doesn't actually appear to be creating a browser tied to that profile, as I just setup my personal sync account it caused all the open browsers (across 3 profiles I setup) to all sign into that account.

So if this exists, why don't they do some minor adjustments to make it usable and call it good? This works rather well (except not telling you which browser is loaded with which profile)