RE: Super Sporster BIPE
My personal experience with other models is to move the CG rearward if you cannot get the model to slow down. Not knowing how the SS Bipe handles being tail heavy, and the fact that you are at already at the rearward range suggested, I would move it back about 1/4" and see how it behaves. If it's better, move back another 1/4" until you find the spot you like best. If the results are opposite what you are looking for, move the CG forward. Another thing to consider is I seem to remember this being a pretty hot plane to land. I don't remember ever hearing that they would slow down very well on final.
John