@duluthralphie
OK, I know you said you wouldn't respond to this, but I feel this needs to be said. First, a clarification. There is wet feed, (usually called "mash" by the old-timers), and there is fermented feed. Basically, fermented feed is just mash that has been allowed to sit and "ripen" for some period of time.
What I feed my birds is more properly considered as mash, because I go through feed so fast it doesn't have enough time to properly ferment. I have about 150 chickens, and that does give me a hefty feed bill. I live in the desert, so free ranging is not much of an option, though I am working on planting desert friendly ground cover that is also chicken friendly.
OK. Wet mash is scientifically proven to increase the length of intestinal villi in chickens. The villi are like little fingers in the intestinal wall that absorb nutrients. Think about them like an inside out French tickler.
Once you have that image out of your mind, the mash (or fermented feed) increases the length of the villi, increasing nutritional uptake from the feed passing thru. Yes, you are right that the Cornish X probably doesn't need more nutrition, but think of it this way, the reason the old timers did it is because they weren't trying to increase nutrition, but get the same nutrition from less feed!
BTW, do you actually live in Duluth? I grew up in Cloquet in the late 60's.