I reverted Master Fader to 1.4.1, used Mackie's technique to force the firmware update (downgrade), and it's been operating fine for 16 hours at this point. I will allow it to run for the next several days.
My test procedure is to close all programs, reboot the iPad, dock it in the DL1608, turn on the DL1608, open Master Fader, switch to Music, play all songs on repeat, switch back to Master Fader, and scroll so I can see the iPad channel meters. I can't guarantee that it hasn't lost sync and recovered while running 1.4.1, since I'm not watching it nonstop. However, under 1.4.3 it never went more than a couple of hours before losing sync and not recovering.
Be aware that if you revert Master Fader, you'll lose all of your presets and everything.