Good questions, Meg. First, one back at ya: Is your coop BIG enough for DL? IMO, a coop must be a walk in style, and must have a proper bird/s.f. ratio, and must have adequate ventilation in order for it to be successful. It won't work in a small or short coop, one with ventilation = less than 10% of floor space, or one where the ratio is less than 4 s.f./bird.
You are right in that a poop board is counter productive to the purpose of a good DL.
Then, a bit of understanding about how composting works: It must have adequate volume, a good carbon to nitrogen ratio, a good blend of various materials of varying size, and enough moisture.
I think it would be very possible to have a nice DL under the perches, while the remainder of the coop space could be more conventional bedding, and not as deep. I've often considered the idea of revamping my DL by putting a retaining board across the length of the coop in front of the roosts. The only thing that has stopped me from doing so is that it would be more difficult to manage when I do push out the DL, or want to do some flipping of materials. (I flip very rarely... perhaps even almost NEVER!) So, my DL is quite deep under the perches. When I add an other bag of leaves, I usually put them under the perches.
I have found that shavings do not work well for DL. When ever I've had them in my DL mix the likelihood of ammonia issues is greater. Since removing shavings from my mix, I have not ever had ammonia issues. My DL is quite moist now, even more moisture in the coop than I like to see. We are past the worst of the winter cold, and I am hopeful that I will not see any more sub zero or single digits for the rest of the winter.
