Comment by qu4z-2

You need to make one shortcut[0]:

  firefox --no-remote -ProfileManager

Then just click that every time you want a new/different profile. It has a list, with Create, Delete, Rename buttons...

I do wish -ProfileManager implied --no-remote though -- I wonder whether there's a reason it doesn't?.

EDIT: I just found `firefox -P` elsewhere in the thread. Also it seems like -ProfileManager does imply --no-remote now. Yay!

[0]: Or a shell script in my case, but a shortcut is probably more "accessible".