Question about Scion/Saboeur ascendancy's "when you throw a trap"

It says "20% chance to create a Smoke Cloud when you place a Mine or throw a Trap".

I assume that the phrase "throw a trap" is shorthand for "when you use a Trap skill", right? As in, if I use Cluster Traps/Multiple Traps, the 20% will still only be rolled once for the skill use, instead of once for each trap thrown by the one skill use?

Jaws of Agony shield has similar wording "x% chance to gain power charge on throwing a trap" and it works separately for each trap (three rolls for multi, five for cluster). So it might work per trap in Scion's case as well. Haven't tested it though.