BV skill effect duration and poison duration

Hi,

Does skill affect duration increase the duration of poison if applied via blade vortex? The sources being from the passive tree.
I've seen a lot of BV builds take skill affect duration on the tree and PoB shows it as a massive dps increase, greater than % multiplier for poison (when set to 10 blades).

Or is it that increase duration just helps the 10 blades be maintained for longer without re-casting?

Thanks

Easy rule of thumb: Unless something specifically says it "increases poison/ailment duration" it won't increase the duration, the only case where that isn't true to my knowledge is with viperstrike due to the skill modifying poison duration itself.