Ambush support doesn't appear to do anything?

As far as I can tell ambush support is doing nothing for either crushing fist or double strike. Missed in the melee patch somehow? I feel like I'm critting 15-20% of the time (my unexerted crit chance is in this range) even with ambush, which should boost my crit chance to 100% if I am to believe pob. Not sure if I'm misunderstanding something about how it's supposed to work, would love if others could corroborate.

While I'm at it, could I get clarification of whether crushing fit hits with one or both weapons at once while dual wielding?

does ambush not work with aoe skills across the board? I think it is working with double strike but I'm missing or not targeting the monster i dashed to