Best way to manage multiple sets of credentials/profiles?

Thanks for the response! I missed this feature since I assumed it was just for switching the MS account associated with the browser but it looks like it's closer to what I was looking for than I thought.

It doesn't work quite perfectly for my needs - opening two separate windows rather than just switching back and forth in a single window feels a bit clunky, but that's a minor thing. Much more importantly, it's treated as a completely different account in terms of syncing, bookmarks, saved passwords and so on which means I have to copy these things back and forth all the time when I'm just looking to toggle sessions/opened tabs and nothing else. A "light" mode for this feature which only distinguishes between open tabs and cookies would be extremely useful, although it's probably too niche to be all that relevant to most.

Nonetheless, even what's currently present is much better than dealing with two separate browsers, so thanks for letting me know!