I use Mozilla's Container Tabs extension for most of this. Unless you specifically want to keep settings/extensions/etc in specific, separate profiles, they're a good in-between solution. In my case, having a single FF instance is desirable as I would juggle between too many profiles which would need similar extensions for completely switching profiles and windows to be a good experience.
I use container tabs in my main profile as well, as like you, I'd have too many profiles if I didn't.
My profile use is about big concerns and work modes. For example my work profile has some developer plugins, separate password managers, bookmarks, and snippets. Doing so keeps everything nice and removed from my home life.
