ORIGINAL: Deadeye
It would seem to me that the CG wouldn't change at all. The retracts are using the same hinge location no matter if they are up or down. It shouldn't matter to the CG.
Try it for yourself. Pick up a 10 pound dumbell and let it hang by your side. Then rotate your extended arm forward, lifting the weight. Even though your shoulder (the hinge point) doesn't move, you will feel your cg shift forward. The CG is definitely affected by the location of the mass, not where it's connected.