I did not know WW2 did any operations with props... I'll have to look more closely. Are you meaning an un-rigged  "static prop" or a non-conforming "posable prop"? My terminology is all muddled but to me a non-conforming posable prop is a muti-part figure that is rigged but does not have a hip as a root part. An example is say an easypose tube. In the case of a shoe it would have a toe bone connected to a terminal foot bone but not follow a phantom IK chain up the hip for purposes of conforming.

BTW Dimension3D has a neat little script for converting figures into static one piece props with one click. Ockham has a similar script called "Furniturize" I think. Very handy sometimes once you have a figure posed to turn it into a prop without having to export/import. If you load it in set-up room and right back out it becomes a figure again and can take standard MATposes.

One hassle with doing it by export/import is loosing transparency settings on the eyes and lashes and probably any fancy shader set-ups there might be while these scripts preserve the material settings as loaded. You just have to remember to save the new prop or prop figure. I often turn my background figures into props to cut the amount of memory used in a scene.