At first glance, the yCenter channels work very well. The picture shows different settings of the yCenterB master, and the resulting zRotations. At yCenterB = 0, the Poser Origin is the center of rotation. You can set yCenterB between 0 and -1, to move the yCenter origin between y=1 and y=0. Or you set yCenterB to positive values, to move the yCenter origin from y=1 towards the sky. However, the yCenter origin only works, if zRotate is zero: To use this variable origin, you have to rotate the prop to the default orientation (all rotations are zero). Then you can choose the yCenter origin. Then you can rotate around the new center of rotation. When you set a Rotate channel, and then try to modify the origin, you can see some displacement of the prop. If there is a preexisting rotation, the yCenter channels will create a visible translation of the prop.