In XCSoar.org we are load free Airspace data files (available most of the world) to help us navigate out of restricted airspace. Very helpful for special areas you might not know about, such as munitions factories.
Was wondering if this is a useful feature in APM Mission Planner. They could either be displayed as an overlay, or help you set your geofencing. Or even warn on the fly for long distance flights with planes.
At a minimum, an overlay on the maps would be good. Help keep you safe and legal.