But how do you make a pinch point completely safe? Especially with a slatted belt that doesn't have a continuous smooth surface? Where it goes under the guard

But how do you make a pinch point completely safe? Especially with a slatted belt that doesn't have a continuous smooth surface? Where it goes under the guard is still a pinch point. Much as I prefer inherent passive safety to active safety, an optical beam or two would work here - machine does an emergency stop as soon as the beam is interrupted.