Yes, free feeding is best, but I do know some people feed meals because they have issues with rodents or other pests.
I don't have any problems with rodents or other pests. I have never seen a mouse in my hanging bucket feeder. I think it would be really hard for them to get into the hanging feeder.
Outside in the run it's a different story. I have squirrels, chipmunks, and rabbits that will get into the run and eat anything left behind by the chickens overnight. But as I feed the kitchen scraps in the morning, it is rare to see anything left after only 10 minutes, let alone overnight.