8.1 Backdraft question

“Backdraft - Conflagrate reduces the cast time of your next Incinerate or Chaos Bolt by 30%. Maximum 2 charges.”

Does this mean it grants 2 charges or you may only have 2 charges of backdraft active? So if I talented Flashover and conflagrated twice, it wouldn’t be 4 stacks of Backdraft, just 2 stacks???

I’d put money on that just being a tooltip clarification, since you can’t stack it up to 3 times when you don’t have Flashover.