I'm not familiar with V4WM's rigging so I don't know why they used geometry for the helper bones. I can only guess that at the time it wasn't possible to weightmap a ghost bone, but I don't know because ghost bones have been a thing going back to at least Poser 7 and I think at least Poser 5, so that probably isn't the reason.

What's more annoying is when trying to select a body part from a certain angle where it's overlapping in view its opposing part and you select the opposing part. The first selection should always be the one closest to the camera or cursor. I suspect maybe it has something to do with how Poser's viewports/cameras work. No clue tho really. I just know that it's annoying and has been persistent through every version of Poser that I've used.