Very off the cuff thought (i.e. an excuse if I say something stupid).

From a programming standpoint, you'd have to have a way to say push the current folder on a stack and pop it off as you traversed the hirearchy - a fancy way of saying keep track of where you are. How many times you'd have to do that depends on how deep the references go. Not a huge challenge but then I say that every time I write code and am too often proved wrong, especially considering that I know nothing of how Poser is coded. It's much easier IMO, to do it explicitly. There's also the matter of handling both formats; again possibly easy or maybe not.

Can you not "simply" change the .pmd reference in the .cr2? It would be easy (I would think) to have a utility that would allow you to drag the .cr2 and the .pmd onto it and have it move the .pmd to the location of the .cr2 and automatically change the reference(s) in the .cr2, or select the .cr2 folder etc. Not as nice as having Poser do it but it wouldn't require re-jiggering Poser's code. Also, I wonder if souch a change might not require updates to other utilities out there that are written based on the current way of doing things,

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