My take is simply this. 100% for "what it is worth" category.
There's no doubt that caloric intake goes up in the winter as the hens are using calories for warmth, not merely egg laying as would be the case in milder weather. I expect production to drop 20% and feed to uptick 10-20%. Since I do not live in a mild climate, I consider this all normal and common sense.
However, my feed is already a very high percentage of corn and grains. Huge percentage, according the Hubbard Feed's own data. Thus, how is giving them the grains, going to make much difference, I ask myself. But, the grains, by themselves, lack the other beneficial protein and other supplements that are in my regular feed. This has always been my quandary.
BTW, on other posts, Lazy J reports having doctoral level training and education in animal science, so while the tone of some responses seem a bit terse, I listen. I consider the source of books I read as well. Just because things are published doesn't mean it is always gospel, of course. We all continue to learn, evaluate what we hear and read, and discover things for ourselves. Best regards.