3D Shapes with Mount Points

I am interested in adding mount points for additional 3D objects to be mounted to a main object. I understand the concept behind doing it, is it possible though?

I *think* TGE does it by noting what objects are mounted in each mount slot, then when the object is rendered sorts everything out. Is it possible to do it this way in TGB? I have a funny feeling that because we're treating it as a 3d object in 2d space that it wont work nicely.