What exactly are you proposing gets tested? The windows are supposed to be hard to break so people don’t fly out of them…
Hard enough to not fly out accidentally but weak enough that people can break them on purpose so they're not trapped inside.
That's what seat belts are for. Making unbreakable glass is morally repugnant.
Hard enough to not fly out accidentally but weak enough that people can break them on purpose so they're not trapped inside.