My solution to both of these has been to create separate .desktop entries for each profile and give each a theme and a custom icon. That way I can know from the window manager which profiles I have open and which one I'm looking at according to the theme. You can then launch a specific profile through the icon, with Super->"ffwork", or with the right-click->open new window if you have it open already.

The main problem is that I have completely forgotten how to do this multiple times across different machines and I never remember which combo of FF flags and .desktop values necessary to get instances identifying themselves to the dwm as a separate program. I think this is correct though https://askubuntu.com/questions/1209434/how-to-display-two-d...