A workaround...
...\MusicBee\Playlists will have all the iTunes playlists in one folder. OUTSIDE of Musicbee, i.e. in windows explorer, duplicate by hand all folders and hierarchies. Still in Explorer, but looking in iTunes, move each playlist to the appropriate folder in Explorer. This is tedious, but I did about 400 playlists in about 2 hours. Kudos to musicbee for simply reading the folder hierarchy that it finds, when it starts.
Maybe you all knew the above, but iTunes sticks all of this in its xml file, which is hard to edit.