If you get a MULTIKILL with a grenade your super charge more if you have that perk on. That seems fair to me no matter what class or grenade you are using. Quintessence Transfer is for warlocks and does the same thing buddy so it's possible to use the exploit with scatter grenades. I, for one, never used the exploit, I just don't like how the made the perk useless. My triple tripmine kills don't count anymore.