Didn't even think about that. Could possibly just 3d print a spacer to fix that

I've been looking for proof of this as I can't imagine how as there is nothing to complete the circuit. You do however increase the voltage at the top and bottom of the pile as you have a load of batteries in series. But as long as nothing completes that circuit then I can see no harm storing them like this. I'd love to see a link to an explanation if this is incorrect.