Attached is the figure I used for the animation, so that you can verify for yourself that the geom switching works without the need for and extra morphs or weight maps. The top dial in the BODY "AltGeom" can be used to switch the geometries. To be absolutely sure this works as stated, try editing the weight map, you should find that your edits persist through the geom switching.

The figure does not use animated joint centers, but you can try that on the figure if you like. I see no obvious reason why animated joint centers would not be compatible with geom switching.