Hmm, how do I say this? You mention the FFA director as if to add validity to that feeding program he advised. FFA folks don't know stuff just because they are FFA, trust me. FFA folks have been extremely disappointing to me on several occasions with their lack of knowledge of poultry. I bought my first rooster from an FFA teenager. His chickens were kept in pens in the woods, dark, dank, pens so full of water that the birds were standing on whatever dry ground they could find, troughs of black water to drink, no sunlight at all could get in. The rooster had been fed only corn, apparently, from the bags I saw laying around. He was a Barred Rock, but there was no white on him, only yellow-gold from his woefully inadequate diet. He had a terrible case of lice plus a fungal infection of the comb called favus. Within a month of proper diet, he did not look like the same bird at all. The kid should have known better. I mean, it was FFA! At least, I thought he would know more than the average person, but he did not.
Later, when I informed a feed store that they had mislabeled an entire brooder of chicks, the excuse was that the FFA person did not correct it therefore I must be wrong. Being a breeder of Barred Rocks for years, I know a brooder full of BRs when I see them, but they were labeled "Domineckers". So, I have had no evidence that any FFA folks know much about anything to do with chickens in my own life.
So, usually, I groan when someone says anything about FFA due to my own experience with the people who run it, and that's my own experience. Certainly, somewhere, there are FFA people who know more than the ones I've encountered or the one advised you to feed those chicks improper feed.
But, folks have already said it for me: Chicks need more protein than laying hens and they do not need the extra calcium. They are growing at a rapid rate and need the feed that has the proper vitamin/mineral boost and protein levels to support their fast growth. So, they may survive being fed the wrong feed, especially if they are able to get out and forage for themselves some, but they won't have the optimal nutrition they should have.
By the way, even my adults get more protein than the average chicken. I feed a 22% layer pellet to adults. Mine are heritage birds, larger than hatchery stock, and I want them to have the best nutrition. It still contains animal protein as well. Corn is 8% protein, not adequate for chicks or adults. Feeding the wrong thing short-term then fixing the issue will probably not cause any lasting damage, but chick starter/grower should be fed until they are close to laying age. I have fudged a bit with teenagers of 14-16 weeks when they had to go in with adults, but I try not to very often.