Linda B220, GameBird feed or Grower feed mash is a good idea to boost protein if feeding mostly Ferment or fodder. What kind of meat do you put out? Cooked or raw? Cat food or your left overs? Fish, beef?
At what age do you start them on Layer feed with the high Calcium in it. Ag scientists say too much calcium too young can cause kidney problems. Most say not till 4-5 months or once they start to lay. Use Grower/Developer/Broiler feed until then.
I would go very light on the BOSS because it is so much fiber like whole oats and can fill them up quicker before they get enough good high nutrient dense food.
As I mentioned, a science teacher I know does an experiment with his class each year on chicks feeding different protein content food until they are 4 months old and weighs them to see development and it makes a significant benefit to get more protein in them and less really slows down their development.
But for lots of us here were are not in a race like a commercial farm and more about having fun, and happy chickens, so I am not saying here is how it has to be, just sharing my experience and study. I like them laying and developing sooner, but not too soon which can happen too.
Right now, I'm using layer feed until I can get to the store. I'm stingy with the BOSS. Maybe a couple of cups to 5 gallon bucket. In fact I made it today and forgot the azomite. Have to add later. I do feed meat 2-3 times a week. Something like roast chopped up and veggies or ground beef. I don't do raw. I could but just haven't . My daughter (whom I live with) owns a dog grooming and boarding shop. We have dogs barking all the time. I wonder if it deters the coons. I haven't seen any lately. I have 11 9 day olds super blue egg layers. SBEL's and 2 newbie at 2 days old. All are on Fermented feed.