That's because gl_polyblend "0" helped disable a lot of the effects of being plagued/blinded/gassed in Q2WF... you can't turn this off now in Fusion.
Gas being direct hit only would't work for the soul reason that it doesn't make sense to only be effected by a direct hit from it... if anything, if you're directly hit, you should *NOT* be effected since the grenade would either blow up prematurely before the gas is dispelled, or it'd bounce off you and when the gas did come out (remember it was/is delayed) it would be out of range, unless you ran into it's range after it bounces off you.
=V3=