While living in Spokane, I had Cornish Cross chickens. i was told that they produced large, more meaty chickens, but that the egg production would not be as good as with other breeds. We always had more eggs than we knew what to do with. The chickens were very large. We fed them grain feed, starch water from when we made fresh flour from Whole Wheat, and they caught insects, mice, or whatever little critter happened to invade the coupe. I once saw these hens go after a live rat that came by from the forest. It was dead and eaten in a matter of seconds, literally.
My hens were not fed corn, nor any blossoms with yellow petals. And yet, the yolks were a deerp orange/yellow color, and the eggs were large and firm, with an all-white shell.
I have to think, based on experience with these chickens, that the varied diet, increased exercise, and subnsequent improved health contributed to the quality and flavor of both the eggs, and the chickens.
But I am not a proficient farmer, and haven't had chickens in a very long time. So this is based on memory, and not very scientific observations. Take with a grain of salt.
Seeeeeya; Goodweed of the North