You can see my roosts - all one level and above a tray which holds a bag of Sweet PDZ. I scoop it about once every-other day with a kitty litter scooper and it takes me all of 5 minutes. Sometimes they miss the tray and poop around the edges, but it's easily scraped up with a spackling scraper from Lowes. Since I put linoleum on their floor - that clean-up is easy too. There is virtually no smell inside the coop - even if I leave it for several days without cleaning. The chickens will walk in the poop tray, but rarely. The PDZ seems to dry droppings out pretty quickly, so I've not had a problem with poopy chicken feet. The other half of the coop floor is covered in pine shavings. I churn those up about once a week - there is some poop in their shavings, but not much since they are usually roosting when in their coop and out in the run the rest of their days. I bought the tray at the local Tractor Supply store - it was in the section with rabbit hutches and dog kennels. They had three different sizes so I picked the one that fit best in our coop and then built the roosts to fit right over it. Don't know if you can tell from the photo, but the tray fits pretty exactly underneath the roosts. The roost stand has a lip on the front to be a "stopper" for the tray and also serves to hold the shavings in place. I rarely have them mixed into the PDZ. If need be I can slide the tray and the roost stand out of the coop pretty easily for deeper cleaning. All in all, we're happy with the design and functionality.
This coop is a great design. I have one suggestion; Change out your roosts to a wider board, 2x4's allow the chickens to sit on their feet, keeping them warmer in winter. otherwise, cool design.