I don't understand how a pour-over coffee cart is going to scale (scale in the sense of one cart serving many customers quickly). It takes 2.5 - 4 minutes to make a pour over coffee, assuming the water is already boiled and the coffee is ground; and there is a limit, just based on physical space, to how many you can have going simultaneously in one cart, right?

The Philz truck in San Francisco seems to handle this alright, but they have 3 people making the coffee and 1 person taking payments, and they're charging 4+ dollars per cup for a known/cult brand.