a) The cooldown doesn't start until after the flight ends. It makes sense for some spells to work that way, but the flight can be 15+ seconds, and the cooldown afterwards is 60 seconds. Unnecessary for it to be delayed until spell finishes.
b) The charge-to-100 doesn't start until after the spell comes OFF cooldown. I realize it's a very powerful ability. However, it's completely uncastable without the 100 stacks. It can take 10-15 seconds to get those stacks.
If the ability needs those 15-30 extra seconds of invisible "cooldown" for balance, fine. But you guys are all about "visibility" lately, and there's got to be a better way to show the cooldown that more accurately reflects when it will be useable again.