I could add contacts one at a time with a different client and have them
show up. Modifying anything through TB was iffy. And of course the
import never worked so I would have to tell all of our customers to
reenter their contacts one at a time, or find a Mac, or get an android
phone, or import them into Roundcube first and call me...
I started to document the procedure to get it working, but it just
looked embarrassing so I scrapped the entire idea for now.