So I've been using Supercharged Gas before blowing out all my aoes because I figured the extra 50% armor penetration would be great for it. Just to check, does it help at all to use it on AoE's like it does single target? I haven't been noticing a significant increase in numbers but that may just be due to how armor penetration works.

It works for everything excepts the Plasma Grenade.

But it is only 10% Additional Armor Penetration, not 50%.