Patch: Tespia 1.2.190

Completely sure? I'm certain that using the skill itself takes a lot of time, like boomerang step. Maybe they've increased the time it takes to attack?

Big Bang has no cooldown and if you were to spam it as fast as possible (would require a macro as you can't humanly press the key short enough), you should be firing as fast as Magic Claw and every other basic Magician spell.

And it's more like PK Starstorm being spammed, m'rite Loose?

With the 71% base Strafe, we might have to look into redeveloping skill builds there since they were all previously predicated on adding points while it still had +2% per level until it reached where it only got +1% per level.