PM 5 now relies upon XMP to store metadata that we used to store at the end-of-file. PM 5 no longer appends metadata to the end of file because it trips up other brain dead applications that can't handle it (theoretically it shouldn't make any difference since it doesn't affect the image in any way).
One of the pieces of metadata we store is the "inferred frame number" which is to say the last four digits of a filename that cameras create (as part of the Exif standard). Since this metadata isn't part of standard Exif we have to store it somewhere, and XMP is the place. So if you are asking PM to create XMP sidecar files for RAW files then it will create an XMP sidecar file in order to store something as simple as the "inferred frame number" (accessible by the {frame4} variable). This is regardless of applying an IPTC Stationery Pad. So we would have to remove the capability of remembering the frame number (because once you rename the file it is gone) in order to NOT write an XMP sidecar (as you have requested) for simple ingests. Sorry!
--dennis
