I am wanting to start building my tractor(s) for my week old cornish x. I have built many (and sold a bunch as well) but this is the first time I have raised cornish. Will these guys utilize an upper deck/coop area on a tractor? I have been building 48-square feet tractors, that should hold 20 birds each. However, if they do not utilize (can't climb the ladder) the upper deck, I will save my money. Can you guys brag a bit and post your tractors for your meaties? I am mostly interested in those holding 20+ birds.