Maybe it is meant purely for bossing where you use it between telegraphed attacks, but in monoliths it just feels clunky to use. You shouldn’t have to press the button again to cancel it and it possibly shouldn’t have a short movement lock after canceling it, or if it does there should be nodes to mitigate that.
As for nodes I would like to see, maybe something behind the spell damage nodes that converted all increased spell damage to increased damage over time. And being able to specialize 5 points instead of just 3 into mana efficiency would be neat.