I have an instant visceral reaction against the idea of a folding bicycle helmet. But after some yogic deep breathing, I can see the idea working, maybe. It’s not like the helmet physically prevents a car from crushing your head, it just holds styrofoam pads in place to absorb some of the impact. No reason for it to be rigid when off your head as long as it can hold the pads in place when it’s on.
Thus, the Morpher.
It’s crowdsourced, and I certainly wouldn’t buy one in advance of seeing the safety test results, but reasonable people can disagree on that.