It's really hard to fit a poop board into a 4x6.i thought about putting them 18" from the left side wall, and 18" and 24" off floor - thoughts?
I'd put a single removable roost along the french door wall (12" away),
put the poop trays on the floor.
Would make it easy to grab the trays and the birds for exams.
Here's some tips about heights:
https://www.backyardchickens.com/articles/coop-stack-up-how-high-stuff-works-well.73427/