I have read an interview with the owner where he said he deliberately added & marketed a bunch of redundant safety features because Americans are afraid of pressure cookers.
I wonder how one properly make a safety valve that works even when smeared by food, or prevent the smearing from happening. Should the valve be really large in cross-sectional area, so that the force a food clot would have to withstand becomes large?
Pressure sensor that cuts off the electricity if pressure gets too high. No more electricity, no more heating, pressure drops.
Another one I've seen on my mom's pressure cooker that she's had for probably 40 years or more, is a physical plug that will shoot out if the pressure gets too high and the release valve gets stuck. Of course, not sure what the potential damage from this plug would be (I've only ever seen it shoot into the pot when it was removed from the stove, and cooled too quickly). But better than the whole thing popping.