I know it's different than a traditional pressure cooker, but it's still a pressure cooker. That's what's causing the pots to blow up. The vent being plugged from overfilling is the most likely cause to the explosions. The confusing part for users is the way the pot is marked. It has a maximum fill line, but that is not for pressure cooking. When pressure cooking, you are supposed to only fill the pot 1/2 to 2/3 full, not to the max line.
I'm not trying to be too critical of them, but just sharing some of the stuff I'm familiar with and learned from my family and friends who use them.