A diet of mostly corn either whole, cracked soaked in water or not, would be as unhealthy for chickens as you eating cookies every meal, every day for life.
Good gravy, you sound just like my cardiologist.
"Blah blah blah, you can't eat cookies for every meal, blah blah blah! "
But seriously, the fat and protein content of that diet sounds way off. A more balanced diet will likely result in smaller quantities of food consumed.
Perhaps your birds have open grazing pretty often? I'm wondering how you manage not to have heavier losses.
Best wishes on resolving this issue. It certainly is possible to make your own feed, and corn, soaked/ fermented/ or dry can be an important part of that especially in winter. But it doesn't sound like you're hitting that.
If you want a solid protein produced solely in house, look at raising red runner roaches or dubia roaches. The nutrient profile on those is way better than mealworms, and they're not much harder to raise. Spoiler alert though, the mealworms I raise? I feed them layer pellets. Simpler to omit the transition to mealworm step.
Also if you see my soybean post on the pheasant category, you'll see that I'm making no attempt to use insects as a primary protein. Despite the stories you hear on the interwebs, insect raising is no where close to replacing chicken and beef as protein sources. The time, space, and labor just doesn't favor raising bugs for food, unless you've got lizards that *only* eat bugs.
If you're feeding purchased freeze dried mealworms, then I think switching to a prepackaged, complete chicken feed is going to be a significant cost savings, depending on how much mealworms you were buying.
