I have 7, 25 week old, not yet laying pullets. They stuff their crops to bulging every morning on their feed. Then go free range and pretty much do nothing else but scratch around and eat bugs, grass, and whatever else they find. They just eat stuff all day, but act starving when we give them any treats. Is it ok that they eat this much? Shouldn't their crops get full at some point and not accept any more food?
I've had chickens for a pretty long time, and I always keep their feeders full. Mine also free range, but only for a few hours each evening before dark. I think your flock sounds very normal. Chickens are all about the food. And treats!