The reason we quit using dog and cat food with corn is because I noticed the Purina we were feeding the cat was coming out the other end in quantity and pretty much not digested. I am sure that cooked yellow corn is not a bad as just plain yellow corn, but not for my pets.The insutability of corn and other grains for dogs is overstated by popular culture. Some corn and soy content is usually well tolerated by most dogs if in moderation.
https://www.akc.org/expert-advice/nutrition/corn-in-dog-food-what-you-need-to-know/
https://www.akc.org/expert-advice/nutrition/soy-in-dog-food-what-you-need-to-know/
That whole article on corn in dog food is not exactly a glowing endorsement.