> How about a sane Profile manager? This is something I use heavily on Chrome. The "about:profiles" UI doesn't cut it.

What's your thoughts on Multi-Account Containers? I think it's better to use if your use case for multiple profiles is to keep sessions separate (i.e., keeping work and personal logins to clearly identifiable tabs / windows)

It's not as thorough compared to switching entire profiles but sometimes the above is sufficient. (ex: your history, add-ons and bookmarks are still under the same profile)