If you look at the analysis on the tag the only significant difference is the calcium. There are minor differences in a few of the other things but I don’t see them as significant. If you look at the analysis for different major brands of Layer, you’ll probably find even more differences. And some mills or even individual chicken owners make their own feed which can be even more different and the chickens do fine.
If you feed them treats, especially green treats, or let them forage, you’ve lost it is as far as micromanaging their feed anyway. Those minor differences in the feed really become insignificant.
Like many others, when I have growing chicks in the flock, which for me is most of the time, I feed Grower with oyster shell on the side. Even when I feed Layer, I offer oyster shell on the side. They just don’t eat it if they are eating Layer.
I think a whole lot of people worry way too much about feeding chickens. For backyard chicken owners, it’s not an exact science. Chickens can do well on a pretty wide range of food.
With commercial operations it is an exact science. They are extremely careful to make feeding as precise as they can so they can manage profit margins. But they don’t feed treats and I don’t know of any of them that feed 20% protein.