IMO, letting chickens eat from a compost pile that includes food scraps is a risky business. What may not be a problem in cooler winter temps could easily turn into a case of botulism in the heat of summer. I give my girls garden and kitchen scraps but - if not eaten in 24 hrs. - whatever remains is removed and put into the compost bin, which they don't have access to.
A caution on feeders in humid weather. I have a large one that is in the coop. It's covered and there's no way that rain or water can get in it. I recently noticed that the girls weren't eating from this particular feeder and - upon investigation - noticed that the feed had turned a gray color. Even without water getting directly on the feed, it had absorbed moisture from the air and was getting moldy! We've had a wet summer and it's been terribly humid so guess that's what did it. I threw the feed out and will only fill to what they can consume in a day or two at this point. I store my feed in a "Vittles Vault" airtight container designed for storing dog food.
I lost a bird last year to what I think was botulism so that may be why I'm so particular about letting them in the compost and moldy feed.