I couldn't test in Poser ATM so I'm glad to see this, though the results don't surprise me. I would have simply tried to import the pseudo-obj as an .obj rather than going through the indirection of using the reference in a .pp2, i.e. to test Poser's .obj import function directly. I assume it's the same code though and would have a similar result. I'm not sure why anyone would 'change' a prop to an .obj and then in effect use it as another .pp2, but it could happen.

As I said before, I see little or no use for the 'trick' in Poser anyway even if it worked. The only (limited) utility I see would be in saving an extraction step if you aim is to get the geometry into another application for modeling, rendering etc. Whether that was a design intention in the case of UVMapper, for instance, or just a happy coincidence, I don't know.

This is the first time I've heard of the idea so I wasn't aware that it was a popular one. I thought maybe it was some odd thing based on the somewhat mutability of Poser file types e.g.  pz2 > cm2.  I guess again, it just seems an odd thing to do for use only within Poser. Nevertheless, it is important to illustrate as you did, why it's not a good idea.

Kawecki's example illustrates another hazard of the 'fake' .obj. There's probably no application other than Poser (when reading a .pp2) that's going to be able to properly distinguish multiple sub objects in Poser's embedded .obj format. Since there's no way to tell beforehand whether a .pp2 contains even one embedded geometry, much less multiple, ones without opening it in a text editor, the renaming has even less utility. It's a quick and dirty way to get some prop's geometry into some applications without using an editor or utility to save it out, and that's about it. Even then, you probably need to remember to make a copy first.

I suspect BB's musings on the semantic limits of what constitutes an .obj were meant more as a thought provoker than a suggestion for practice. At any rate, when it comes to what one can put into an .obj, one should follow the old joke (ladies avert your eyes)  - 'Confucius say that woman who ride astride is stretching a good thing too far.'

Now, having lowered the tone of the discussion to a sufficiently low level, I'll slink out :-) 

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken