There is no practical way for us to feed a rooster separately from the hens. The adults can handle the extra calcium OK anyway.
Something to consider that might make you feel better. It is not the percentage of calcium in the feed that causes the problems with growing chicks, it is the total amount of calcium they eat. A rooster or a hen not laying will not eat nearly as much feed as a hen laying an egg every day, so they don't eat as much total volume of calcium.
Instead of feeding Layer, some people feed Grower or Flock Raiser and offer oyster shell on the side. That way the ones that need the calcium for egg shells can get it and the others don't eat enough to matter. I do this when I have a mixed age flock with some growing chicks mixed in. But for an all adult flock, it is not really necessary.