For anyone here who’s fought the “Unsupported File” wall loading sample packs onto the MkII: I made a small Mac app that batch-converts a whole pack to the 16-bit WAV the SD import actually accepts, and tells you in plain language what it changed. I wrote it up over in Sandbox so I don’t clutter this thread: It's 404, yo!: a small Mac app that makes any sample pack SP-404 MkII-ready
Happy to hear if it trips up on anything on your end.