Layer was built to be the minimum (expense) feed for commercial chickens of the 60s, 70s, 80s under commercial management methods below which economic losses in birds, egg production (size and frequency) were not offset by savings in the cost of feed.
If you aren't raising 60s, 70s, 80s -type commercial layers (chances are almost 100% that you aren't), under commercial management methods (you aren't), with a sole interest in maximizing profit (you aren't), than the studies responsible for the "layer diet" don't exactly fit your needs. ...and even if you were doing all those things, the birds of today are far better than the birds of yesterday in terms of egg production (and therefore dietary needs) and the cost inputs have all changed.
Its useful science, and a good starting point. Not, in my view, a good place to stop after reading the word "layer" and concluding its a perfect solution for your situation. As some do, and the largely ignorant farm store employees often recommend.