I'm not sure if it's design or just manufacture, but you're right that it's just for the prototype cans and not for production. People underestimate the amount

I'm not sure if it's design or just manufacture, but you're right that it's just for the prototype cans and not for production. People underestimate the amount of man-hours it takes to manufacture one-off products, and that's before you consider the price-hike that happens whenever you sell to the government