I've looked into it.
Six years ago we introduced the logic to immediately destroy an air unit as it crashes outside the map:
This was to fix a bug related to intel, where the OnDestroy
of a plane was not properly called in the situation where the plane crashes outside of the map where there should be 'water'. The plane sinks indefinitely as there is no ocean floor. Which I suspect causes #848 where you can get infinite intel.
I can reproduce this by reverting the commit, add logging and then make a plane crash outside of the map.
The fix is not as simple as just warping the wreck back into the playable area. Take as an example a campaign map: the playable area can be extended / shrinked and therefore warping the wreck is 'incorrect' and will break immersion.
I'll have to think it over.