Had the same thing happen with dress shoes a few years back. Guy I trust told me the leather was getting cooked from going back in the heat again and again, and the clips would never sit right after that. Started doing those cold and the fit held way better, no more callbacks. Heat still has its place for boots and heavy stuff where you need the stretch, so its not like I threw the torch out. But for thin leather and anything I redo a lot, cold just works and the clip stays put. Sounds like that old timer knew what he was talking about.

Kept a paper backup for years and still do on remote digs. Batteries die, clouds don't always follow you into the canyon.

Two years of pointing my camera at the wrong spot, my Polaris game was strong but my results were trash, lol.