I don't need to be a film maker to critique a film. OP makes no claims of his/her superior engineering skills, only provides typical concerns that people have.

That is a totally false equivalence. You need to be a film maker to make a statement like "shooting film on medium format is so much harder than people think". Especially when you're armchair critiquing a professional film maker who shoots with it every day.

I made no claim of the type you're implying, although I do work in the automotive industry. My comment was strictly related to history - A123 Systems was also a company of electrical and mechanical engineers attempting pretty much the same thing, and they failed nonetheless (you can look up the history if you're curious). My point was that technical expertise is insufficient on its own to guarantee success in areas like this where a minor manufacturing defect can brick cars or light them on fire months after they leave the factory. That's what extensive QA at scale means - every single battery that gets sold has to be extensively checked for performance and safety or else you get Galaxy Note 7 or A123... again.