My experience has always been that if you want a volume boost on a fairly overdriven amp, put the booster in the loop. This can be an EQ, clean boost, or whatever.
However, if you're running pretty clean it probably doesn't matter that much, unless you really don't want to change the shape/gain signature of the signal. For solo boosts I don't mind a little more dirt on the signal if I have a decent low-gain thing going, so most of the time I can get what I want with my EP Booster in front: it gives a hair more mids and usually gives just the right amount of extra juice and a slight bump in loudness.
But if I'm already pretty dirty, boosting in front just makes a mess of things and it gets more distorted, but not really any louder. Definitely not more audible, which is usually the goal. So in that case, it makes way more sense to put a clean boost in the loop (like your EQ). EQs make great boosts, obviously.
I see in the manual that the recommended MV setting is between 9:00 - 2:00, and that any more can overdrive the fx loop. So there's that to consider.