You know a high vis vest and a lock pick for a circle key is only about a hundred bucks. I’d put money on the fact each vending machine probably has the same key too. Once you pick one you just tighten the pick and now you’ve got a key to the rest. You can stand right in public and take your time emptying it. People will just assume you belong. To be fair, if you’re try to look like a vending machine employee you could even skip the vest. Just bring a trolly and some milk cartons.