"Cooldown"

It can't be the smokescreen duration since I count it at rank C at ~3 seconds.

Does the debuff itself have a duration? Or is it permanent until the mob dies?

Nevermind, answered this myself, however it does not seem to match the duration values in this chart (30s @ Novice)

The duration listed, as said before, is supposedly for how long the cloud lingers for.

supposedly?

Clearly it is not if both Meru and I have gotten results that indicate otherwise.

Don't forget that the stuff was pulled from JP Wiki and/or JP Testers before NA got Ninja.

The values are still 5. They have not changed.

... Okay?