According to the informed sources I used to work with no Argentinian fast jet ever got into a rear-hemisphere position on a SHAR, so there would be no actual need to do so. Other informed sources I still work with suggest that VIFF was unlikely to be used in combat unless/until someone dreamed up a way of doing it without destroying the kinetic energy. They state categorically than no fast jet pilot would ever deliberately lose that much energy in close combat.