What is your coop like? That will determine what will work for you. If you are designing specifically to harvest poop then I think the best thing for the roosts seem to be a pit under them, with a wire screen over it - where you would have a poop board but it doesn't need to be cleaned out so much. That only takes care of what they poop overnight but harvesting what they poop during the day is pretty difficult unless you keep them very confined. Mine don't free range but they are in a large run with lots of greens thrown in which they eat what they want from. the rest of the greens composts in with the poop and makes a great garden enricher. I just dug 6 months out which was about 20 wheelbarrow loads. Great stuff. You have to have a lot of chooks to make any money out of it though.
Every single weeds I pick out of my 2.5 acres garden.The girls get lots to choose from so they are pretty picky. They love clover and chickweed but that is only a small proportion of what they get. They don't get much in the way of grass clippings. I use a ride on so the clippings go straight on the grass. i work on the principal that chickens won't eat what is bad for them if they have a choice so variety all the time is the best.
We keep our chickens on hay and straw. Once a week (in summer) and once every other week (in winter) we rake their whole yard (20 x 20) and put it all in the compost. We use deep litter in the their house so that only gets moved out every three months or so. We also have rabbits that are on wire mesh with a tray to catch their droppings underneath. They go straight on the garden beds though and are a lot easier to harvest. Our compost piles also get the goose and duck pond dumped on them with all of those yummy drippings too. When it was hot out this past summer we made a compost bin 8l x 5w x 3h, dumped in all the chicken hay and straw along with the pond tailings and a few grass cuttings and sticks and twigs and it was steaming. We started using it only a month after our first pile was finished stacking.
Ahh, composting. One of my favorite subjects! We live on 10 acres but our only livestock are our chickens. I collect from the girls once a week, inside and out of the coop because the coop is a little small I want to keep it fresh as possible. I do collect poop from a girl down the road that has 101 rabbits, (just so she can say she has over 100), and any multitude of goats, calves and a donkey. i end up usually with close to 400 pounds of manure a week! My oldest pile is 10 ft x 10 ft x 12 ft high. Once a week with the front end loader I go out and toss it around. My new pile isn't that big yet so I don't do anything with it until after winter. This helps get the right balance before I start mixing. I alternate between these 2 piles on a yearly basis. Our garden is 200 x200 and I sell our extra produce to a gentleman that operates a veggie stand a couple miles from our place. Thinking about a third pile!
I just get my square and shovel out old poop and put in new pine shavings on a regular basis.No science in it.Then the old stuff gets jettisoned,catapult style, into the garden where it gets watered down with duck and fish water.