It's not EQ that causes your dps to drop, it's movements. In theory, your multiple target dps should always be higher than single target because there's additional targets affected by CL & EQ, and you get multiple flame shock dots that gives you 2 or 3 x more lava surge procs.
So please refer to my first reply about what can you do to maximize your dps while moving, then read this one, which will be on AOE.
single target, EQ is a minor increase than an unbuffed LB, but it's soooo minor that you don't have to strain yourself by casting EQ. (if boss moves out of the area *such as K