Way back in Burning Crusade I played my mage a lot and one of the core addons I used was an add on that caused two things.
1: It expanded the cast bar to take up a lot more of the display and be able to place the bar anywhere.
2: and the main thing was that it showed the cast modified to show when the spell is available to cast again modified to when the cast happened in regards to latency.
Does anyone have any idea which add on this was and hopefully without having to install a UI changing core add on.