pardon, but for  the user how would this be different than just using a cr2 setting?  other than needing to switch library folders to either the over-crowded pose folder or the unintuitive prop folder?  it seems like a lot of effort to get around using a method i've never heard anyone complain about. 

in terms of bugs, i can't really detail any at the moment.  i kind of just go around obstacles when i'm working on a scene, so unless i encounter them consistently, i don't really notice particulars.  i know the two products i have with geometry switching i avoid due to bugs, but i couldn't tell you what they were without a new bout of testing.  i haven't been doing much 3d in a while, and what i have been doing is testing different cloth modeling techniques, so i'm not very prepared for Poser testing.  but i'll give it a shot when i have time.

edited to add:
i emphasized user because it seems like you're trying to get around the developer issue of having 2 cr2 files.  it seems to me that this is something you could automate?  if you're just generating a new cr2 with a replacement of one obj reference with another.