They probably have enough space to fly down, most of mine do but some like the ramp.
I added ramps to board and nest perch because I started with some big clumsy birds.
See pics on my coop page.
Same dimensions as I have. Some take some shots, but figure it out.
Most roost on roosts, some roost on edge of board, some roost on the board itself.
The 8" give me enough space to clean with how and basket sifter.
Here's some posts about it, they're kind of old, but changes are noted.
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