This is about a Weight Shift aircraft. 9000 hours and I have never flown one. The only ones that I know of are Ultra-lights and thus do not require a pilots license. The good news is there are no questions on the FAA exam that directly relate to this.
Second this is not simple to answer via e-mail. The problem is we think of Weight and Balance as two dimensional. Weight is the total of what the aircraft loaded weighs and balance (center of gravity) is the point that the plane would balance teeter toter like on a post. GG is normally about 18 inches behind the firewall or near the wings. This is the reason that the main fuel tanks are normally in the wings. Fuel load can change with out significantly changing CG.
Reality is CG is three dimensional. A plane being top heavy ( High center of gravity )is the most precarious. High wing airplanes tend to be the safest trainers because they have a lower CG. Experiment. Take a paper plane and tape two coins to the lowest point bellow the wings on it. Turn the airplane upside down and gentle give it a toss up in the air. What happens. Answer: The plane should right itself. Now take the coins off and tape them to the top of the wings. Gently toss the plane. What happens. The plane rolls upside down and noses into the ground. OUCH. You and I are the coins. Thus the reason that 99% of all flight instructors have done their initial spin training in a high wing airplane.
In a weight shift aircraft you are hanging like a pendulum under the wings. Properly configured with the CG below the center of lift. Speed up and the the weight shifts backwards pitching trim up. Slow down and the weight shifts forwards pitching trim down. It naturally controls the pitch trim. Thus, You will never see a low wing weight shift ultra light.