FWIW, I've found that mixing cracked grains, sprouted grains, fermented grains, etc. all help them gain weight without the stupid eating usually associated with CX. For example, I was growing up some heritage birds for meat, & someone could no longer keep a dozen CX they had, so I brought them in. I was not about to change my feeding habits of 100 to accommodate 12, so they were brought into the (organic) program.
Well, don'tcha know, the CX were hopping 2' up onto roosting bars, foraging, etc like real birds. They ended up about 75% of the weight they would have been otherwise, but they were a healthier bird.
Personally, I believe they put excitotoxins (look it up) into their feed like they put it into human snacks.
In summary, if you can get closer to nature in your feed (and your bird's feed), everybody is healthier.