My experience with a CAP231EX
I found that when I moved the CG too far aft that my Sig CAP231EX was very difficult to land. One thing about aft CG though, if you get it too far aft that doesn't mean you'll automatically crash. If the tail is too heavy you can get through the test flight by pressing the elevator down and manually managing your airspeed. The only thing you have to know about flying with a too far aft cg is that if you pull the throttle back, the plane will get too slow ALL BY ITSELF with no up elevator. You can keep the speed up by correcting the pitch attitude with judicious amounts of down elevator. It feels weird, but the plane still flies. To flare for the landing just let go of the elevator. If you get the CG so far back that it's beyond the lifting power of full down elevator, you'll need to keep the power on right to landing. which will increase the lifting power of the elevator until you can get it down lower. -Tom