Making a duplicate or tripple or even grater folder structure in the poser runtime just because the extensions are different does not make sense if you can load any file extension in the Character Library, even see the Thumbnails if it is a Pz Mt PP extension, got a outfit with Props well got em all with the outfit at the same place. Saving files is a different thing in Poser but after saving just move these to the appropriate place so you are sure to find em again.