Over the long term, no.
Over the short term, damage is minimal and generally not observable. How long do you plan to keep your Roos for before rotating them out of "production"?
I feed my flock in ways I generally don't recommend for others, consequence of which that I accept an average 2.3% average calcium in my feed. By 18 months, when I butcher my roosters, I can find some signs of calcium build up, some of the time, on their internal organs. In a clinical setting, I'm sure I could find evidence of excess calcium every time - I'm speaking only of what I can see and feel.
3.5% calcium is 50% higher on average - I would expect there would be more evidence, and greater impact on your roosters as result. But if you are only keeping them for one or two breeding seasons before rotating them out, that could be an acceptable risk level for you.
Note that i do NOT use that same feed for my hatched chicks - that much calcium WILL have obvious consequence on their rate of growth, final size, and other health issues as well. In my flock, the transition to "adult" feed generally occurs at 8-10 weeks, and they free range acres besides, which helps further buffer their calcium intake.
Finally, calcium carbonate (the calcium form found in oyster shell, popular here in the US) is the most damaging kind. dicalcium phosphate and calcium diphoshate are more expensive (thus not as widely used here) but also less damaging to your Roosters. Both are more popular calcium sources in places with fewer oyster shells locally.
Hope that helps.
