"Despoiler" Support Gem isn't working on poison clouds.

As per title, poison clouds are a ground effect (as evidenced by thematically-linked "Suffuse") but do not have their duration extended by slotting in "Despoiler".

I've only tested poison cloud generation (both in tooltips and actual field testing) on Gas Grenades. I'm assuming the inefficacy of "Despoiler" applies to Gas Arrows as well; but someone else can chime in about this if needed.