and i'm sorry i just cant agree with you there especially when it comes to my geckos. i'm a ferm believe that all of my animals evolved to cope with certain condition in the wild and if those conditions, especially in diet, varry to wildly there bodies cant deal with it well. hell this is why i use RO water with my A. Felinus because thay cant handle the heavy mineral content in normal tap water and if i did use tap water on them i would kill them prematurely if used over long term.
Also I'm not saying you cant use dog food or such to feed you pet roaches because i could care less. I'm just saying know the dietary requirement of your reptiles and go from there on what you feed to your feeder roaches.
Edit: also high levels of uric acid aren't great even in animals (such as humans) who can excrete excess uric acid which most roaches cant as i understand it so it build up in the body over long term.