The EQ wil not "fix" any DAC deficiency. It is not the DAC. It is the source, the room, and your ears. Differences between a cheap Dongle and a $50,000 DAC are small. Audible yes, but small. Few can hear the difference between an Atom+ and any high end DAC without good headphones. A couple dB eq off in the midrange is HUGE. Depending on the room, a gentle roll-off from 6000 can be very beneficial. We are not as sensitive in the bass.
I was looking at the Lokius, but I need a narrower cut around 3100. That human programed baby cream overtone that makes digital sounds so rough, brass brash, and some voices over sibilant. It is centered at 2K and 6K. Based on pink and MLS measurements in the room, the centers on the bass are not quite right either. So, one alternative is an old school parametric, which I don't think you can get one you would want, a 31 band pro that sounds like crap, or go digital. As I source off a PC, that works for me. I would not want to run into a A2D, eq, and D2A. That said the newer MiniDSP is getting quite good reviews.
So, yes you want EQ, but do it for the right reason.
I have a JDS Subjective. I was thinking about buggering it to the three trouble spots in my system. 3100, 400 and 600