On the subject of topology and rigging...  I find this to be a pretty murky issue.  In a thread on another forum the topic of re-topology came up and someone pointed out Daz had issued a statement saying that it was Ok to manually copy a mesh's topology but transferring it automatically was forbidden.  It sounds silly to me to think I can do something one way and it's permitted, but if I do it another way it's not.  Usually in copyright issues it's the final work that is judged for its similarity...  But according to Daz, at that time anyway, they were not concerned about how close the meshes were just that the mesh was not created automatically.  I think rigging would have to be a similar matter.  Using the V4 rig as a donor might be forbidden, but it seems to me a functionally exact rig could be created using Poser's set-up tools.

Makes me wonder if mesh makers and riggers don't use the old cartographer's trick of making deliberate errors in order to catch people copying their work...