The jetway, since V2 is out, seems to undock automatically when the passengers are all on board.
In the Maddog X however, the jetway is also the external power supply to the aircraft, so while you're busy setting up the aircraft the boarding finishes, the jetway immediately undocks und the power is lost, leaving you in a dark cockpit. A simulated ground com asking if it's ok to remove external power before undocking the jetway (or at least a clickable dialogue) would be highly welcome..
All the best
Matthias