I was playing Zilean and I had both Transcendence and Cosmic Insight for my runes.
In the game I noticed that I had purchased 30% CDR, plus 10% from Transcendence and 5% from Cosmic Insight (TLDR I had 45% CDR). After I noticed that I was not getting any Extra AP. After I got 10% more later I did receive 20 AP. So it isn't broken, just not as I would have intended.
Transcendence gives you adaptive force per CDR above the cap
When you have Cosmic Insight, the cap is 45%. So you don't get any adaptive force until you surpass 45% in that case. You still get the same amount of adaptive force for having the same items. Cosmic Insight is neutral in the adaptive force equation because it both raises the cap by 5% but also adds 5% CDR.
I had a bug where I had cosmic insight and still had rounded CD % instead of current CD + 5%. Like, those 5% CD can be a difference between life and death.
