That's for knife-edge flight, I believe. With the airplane on its side, the fuselage becomes a "wing" ... more "wing" area ahead of the CG means the rudder can more easily pitch the front end up, and the airplane won't sink into the sunset as quickly.

Full-scale airplanes might make use of this fact, except there's a real pilot in there and he/she can't fit above the engine compartment. Also, full-scale airplanes need to have the pilot positioned very near the CG, so different-sized pilots don't cause big changes in balance.

See, we modelers have it easy!