I wonder if some players can test this for us?
The test would be;
You have a ship docked within a ship (parent-child relationship)
You have a supervised co-pilot droid in the cockpit of the parent ship
You make a quick sublight side trip to an adjacent system grid
While traveling in sublight, you move your PC into the docked ship
You move your PC to the cockpit of the docked ship
You select cockpit control of the docked ship
The debate seems to be whether the parent ship continues sublight movement in this case;
If the parent ship stops sublight movement, then you should be able to undock the child ship and fly off.
If the parent ship continues sublight movement under co-pilot droid control, then the next question is;
Can you undock the child ship from the moving parent ship?