I'd start by sanding it down to get rid of any splinters and sharp edges that could hurt birds,
then adding a perch about 8" out in front of nests for much easier access for birds.
Can't really speak to cleaning as I don't clean my coop much,
just maybe scrape off the big and/or wet turds when I see them.
It's about impossible to keep all turds off everything...poophappens.