There is a concern. Layer feed has excess calcium so the hens that are laying can use it for eggshells. Non-laying birds like juveniles, molting hens, broody hens, and roosters don't need that excess calcium. There have been studies that show the excess calcium can possibly cause harm to internal organs. Not always but it can. They feed that amount of calcium to test chickens and cut them open to observe their organs, kidneys and liver specifically. Some, not all but some, can show damage after a while. It does not affect all of the birds, many that are affected never show any problems. But some can die from it. If the chickens also eat a lot of low-calcium feed the calcium in Layer is less likely to hurt them. Say they forage for a lot of their food then they aren't going to eat as much Layer as a chicken that eats nothing but Layer. One bite won't kill them, it's a factor of how much total calcium they eat in an entire day and even then it is averaged over several days.
Many of us with a mixed flock with some laying and some not laying don't feed Layer. We may use Starter, Grower, All-Flock, Flock Raiser, or something else that is low calcium and offer oyster shell on the side. The ones that need the calcium for the eggshells tend to eat enough oyster shell and the ones that don't need it for shells tend to not eat enough to harm themselves. They still need some calcium but not a lot so don't panic if you see them eat an oyster shell.
The Grower you feed has the nutrients they need but the other stuff are considered "treats". There is a rule of thumb that 90% of what they eat should be normal chicken feed to give them a balanced diet with all the protein, minerals, vitamins, fiber, and fats that they need. Another rule of thumb says that if you limit their treats to what they can clean up in 10 to 20 minutes you are staying within that 10% allowance.
If yours forage for much of their food all of this is out of the window. You have lost your ability to micromanage what they eat. Studies have shown that they are pretty good about managing their diet when given the options as long as they have reasonably decent forage.
Some people believe you need to cram a lot of protein into them. For some chickens like Show Chickens of Meat Birds that can be important, but for the majority of our flocks I feel it is overkill. As long as you don't get ridiculous about it the extra protein will not harm them so if you want to then go ahead. I just don't find it necessary or especially beneficial with a lot of our flocks.
This probably sounds complicated and you will find others that don't share my opinions. That's pretty normal on a forum. My main suggestion is to change the Layer to something else, probably Grower, and offer oyster shell on the side. I'd mix the Layer and Grower until that bag is gone. No need to waste it.
