Roost height

[rosemarythyme]

If you're worried about them flying down from that height, you could move it down to match the top of the nestboxes.

I have never personally seen a chicken fly down to a lower perch before going to the floor,

x2. They'll fly down, so move the roost down low enough so they can safely land without crashing into the opposite wall - just above the nest boxes should be fine.