They don't mention = they weren't concerned. Yes normally it's primarily the vertical axis but you don't want these layers slipping sideways in case of light ea

They don't mention = they weren't concerned. Yes normally it's primarily the vertical axis but you don't want these layers slipping sideways in case of light earthquake. Or water from outside getting in not only messing the electrolyte but also causing whole thing to swell. There are plenty of potential problems, needs much more r&d.