User blog comment:Lukeatlook/Pyro's Item Overhaul 5 - Supports and the CDR Overload/@comment-1748472-20140719142130

What if selected CDR items had a passive that goes like "For each percentage of CDR this item provides over the 40% cap, you gain instead."

For example, if you buy Mikael's Crucible but already have 40% CDR, it doesn't provide any additional CDR but 180 mana instead (For each percentage of CDR this item provides over the 40% cap, you gain 18 mana instead.).