I plan to use a 3' long 2x4 mounted horizontally (hens sit on 4" side) for the roost. This will be mounted about 18-24" off the coop floor and about 1' from the wall. My poop tray will be 1' wide by 3' long, with 1-2" lip to contain sand/sweet PDZ. How does all this sound so far? Should I center the poop tray under the roost? Or should it be offset towards the wall, anticipating that the hens will roost facing out into the coop? Thanks.