@ChickenCanoe
What do you think of mixing layer and starter to reduce the calcium levels for the Roo’s, I worry that keeping everyone on the 22% unmediated starter would be maybe potentially unhealthy as well?
That is a good approach. It isn't an either or situation.
It is important to know that all chickens require essentially the same nutrients all their lives. There are subtle differences in vitamins, most minerals, fats and fiber - depending on what is being fed(age, sex, species).
Where the dramatic differences are is protein and calcium. I frequently mix feeds.
What you are suggesting will work. Mixing layer with starter at about 50:50 will net a feed that is about 2.5% calcium and 19% protein. That will be better for all parties involved.
Baby chicks can make use of 22% protein but they quickly outgrow that phase.
I know plenty of people here feed what IMHO is excessive amounts of protein and they will disagree with me.
Roosters are not only better off with about 1% calcium, when mature their sweet spot is about 13-14% protein. That type of feed isn't available to the general public. However, commercial breeders of egg and meat birds who feed their males and females separately, produce just that type of feed in their mills for the males.
While excessive calcium will cause urolithiasis and eventually visceral gout in most lines of male chickens, excessive protein will cause articular gout.
Any protein above what a bird can use for body growth and maintenance will end up wasted in the feces and becomes ammonia in the bedding.
I may be blessed with 3 feed stores within a half hour from my house and between the 3 there is a good variety of feed. I used to have access to more variety when I had a feed co-op but I can't currently buy enough feed to make it worthwhile.
Something that is sold in the US is Finisher Feed. That is usually 15% protein. It is adequate for birds in the 14-18 week age group and the last week or so of a broiler's life.
Purina makes a 12.5% protein game bird maintenance feed and if I'm feeling wealthy that day, I buy it to mix with other feed for my roosters.
I usually have between 30 and 100 chickens and I probably don't buy more than 2 or 3 bags of layer feed a year.