Thank you for taking the time to leave such an informative comment about the iPhone glass and the use of the material's natural 'sag' in automotive glass.

I remember the water glasses at school dinners that when dropped (I only dropped a few in my time) shattered into tiny cubes like you describe, for the same safety reasons. And here's a previous article I wrote for Signifier that mentions Bakelite - may be of interest: https://medium.com/signifier/do-you-speak-design-c3d51e56757e