My bloviated meandering follows what Sailfish graced us with on 3/8/2021
Added benefit. Above method also easily imports 52.9esr passwords which
had been prevented somewhere around Fx75.x.
Lastly, if extra cautious, delete imported bookmarks (Favorites) and
passwords from Edge. Note! If one uses Edge with other passwords and
bookmarks, this method will remove them, too. So, back them up before
importing Fx bookmarks/passwords and restore afterward. Since I don't
use Edge, this is not a problem.