This is probably too simple, but whatever you create, how about an additional feature that runs through all the Poser files in your Library folders, and automatically changes the version numbers so Poser 4.03 users won't get that bloody "newer version number than expected" message. Come to think of it, that'd make a nice feature for P3dO Explorer. I'm already using it to convert PNGs to RSRs for Poser 4.03; that'd save me another step in the process.