For what it’s worth, two big support issues specific to the the Pixhawk 2.1 would be to supply JST connectors (Pixhawk 2.1) rather than the Molex connectors (PixHawk 1.0) and, perhaps, update your assembly diagram for the 4’’ acrylic tube to accommodate the higher form factor for the Cube in the PixHawk 2.1.
Your input really saved my cheese.