Mike, take a look at the photos Bill has posted. There appears to me to be something missing from your swivel where the shackle is attached. Mine, like the one in the photo, has a spacer fitted to keep that shackle away from the foil. It would seem to me that if that shackle got pinched or caught sideways it could cause some scratching/damage to the foil up there.
Secondarily, I've tried a soft shackle at that point and even after polishing the pass-through point as best I could, it chafed very quickly so I think the metal shackle is the better idea.
SM 209, Adagio
Galesville, MD USA