Welcome. I think it depends on what you want to accomplish.Chickens can "survive" on lots of things. Think back to the old time farmers, some hardly feed their chicks at all, letting them survive on what the horses missed. I have a cousin who is a commercial egg producer, they mix their own feed by the ton using a computer . From what I can tell (and I am no expert), mixing feed ratios is very complicated and is not something the average backyard chicken keeper can do.
However, what you can do is supplement the feed you give to full grown birds. I have a trio of RIR that are completely free range during the day. I give them a small handful of 3 grain scratch once or twice a day just to keep them near the coop, and also give them treats. I can tell you they eat far less layer pellets than my trio of enclosed bared rock chickens, and they still give me two eggs a day.
Hopefully others will post their experience because I am very interested in growing my own feed. thank you for posting this question. looking forward to others answers.