Mesmer skill idea

I've noticed some talk about how fast casting needs some work on becoming a more effective primary attribute. Several fast casting skills don't seem to fit the attribute and the attribute on it's own is probably one of the most subtle primaries there are in the game.
Here's an idea for a new FC elite that fits nicely into fast casting and doesn't require maxing out the attribute to be used well.

Chronomancy Stance - Fast Casting Elite Stance
While in the chronomancy stance, everytime a spell is cast within X seconds of another spell, casting speed is increased 10% in a cumulative fashion.
If the caster fails to cast a spell within X seconds of another spell or the cumulative casting speed reaches 100% the chronomancy stance ends and caster suffers from exhaustion.

very interesting idea but ways to exploit it would be unbearable, like a fast cast AoE smiter? that makes balth aura almost instant cast?

I dig it. But cap the percentage to 50%. And the window for casting to keep it going must be low. Like 3 secs starting at 12 FC.

Interesting idea, however I can see this being used by non-mesmer primaries as well, any class can spam two or three quick spells and then use their faster cast time for something else. In other words it could be used just as effectively without needing any fast casting attributes, although it's definitely viable.

I like the concept though, it would need lots of testing.

Maybe a higher fast casting attribute lowers how much energy is lost from exhaustion afterwards? That way if you don't have high fast casting, you'll use up a lot of your energy reserve from exhaustion using this stance.