I never leave feed in my inside runs at night - mainly because of rats. Can't hens survive overnight without food? I don't leave them water either.
Yes they can survive overnight without food. The problem we are trying to solve, which I have obviously not explained very well, is that they do seem to need some time during the 24 hours with ad lib feed available. They are fully free range once let out in the morning, and the ducks would steal any feed we left out. So the place and time we want them to have their ad lib feed is in their run after they get up and before they are let out. We have tried fitting in the first person up putting out feed for them in their run and someone else later letting them out, but we haven’t managed to make that work very well. So a rat proof feeder we can leave set up in their run, ready for them to eat when they get up in the morning (long before most of us are awake), seemed to be an option worth exploring.