V4WM builded on the experience gained with AntoniaWM. With AntoniaWM it became apparent that each bone needed to have some geometry atteched for some functions in Poser to work. From the top of my head it had to do with the symmetry operations but I am not sure there. For that reason in a service update some dummy geometry was added inside the figure. The vertices for this geometry were added manually at the end of the vertex list so vertex order remained the same and existing morphs and weight maps would not be affected. V4WM therefore had the extra geometry for ghost bones built in from the beginning.

Later Poser updates made this dummy geometry was not needed anymore.