Yes, indeed it would be good to know, and he should probably figure that out soon at a reasonable altitude. In an off airport landing in this plane, obviously the prop is a write off. Until he knows the stall speed and behavior, probably the best that could be done in an off airport landing would be to get it quite close to the ground and then keep pulling the nose up and bleeding off airspeed until impact. Clearly, that requires a lot of flat.If the engine fails at 500', whoever's flying one will be VERY interested in minimum flight speed for the off-airport landing. 500' is probably out of the envelope (low) for the airframe 'chute.