Commentaire officiel
Since your aircraft does not support waypoints it cannot execute Connectionless flight which is what gets rid of the overflight since the imaging is not controlled by speed.
With your Virtual Stick aircraft you should slow down to the minimum flight speed (2 m/s) to minimize the overflight. It shouldn't matter much anyway since it is such a small area. Then shrink your boundaries as needed to accommodate the flight path.
Limiting your flight to just the roof line is not likely going to give you very good results.
Depending on where you are there is no reason to be confined to just the roof line. As long as you are not causing a disturbance, invading someone's privacy, or creating a safety hazard you are likely within your legal rights to fly where you need to. The air is generally recognized to the the FAA's jurisdiction. This may vary state by state though...
