Xonar Essence Muses Edition

I currently have a Xonar Muses Edition as my DAC/amp here at work driving some HD650. I am planning to buy a some sensitive, closed headphones (Meze 99 or PM3) too drown out the aircon during summer. The Xonar sounds fine with the HD650 and the gain is not to much. However with my more sensitive headphones the gain on it is WAY to much, meaning there is some channel imbalance at low volumes on the volume pot.
Any thoughts on how the Modi 2 U and Magni 2 Uber compare and especially how is the gain on the Magni 2 ?
Have there been rumours of the Modi/Magni 3 yet?

 

I'm probably pointing out the obvious, but there's a gain switch on the Magni 2 for a reason (I remember it being a complaint with the 1, to an extent)... Doesn't the Muse let you alter gain via it's software?

 

I am just concerned with the amount of gain. The O2 which I used to have, also had to much gain at stock for IEMs even on "low" gain. The Muses gain can also be adjust via jumpers, but still too much I find for my more sensitive headphones.
The Xonar allows gain to be altered, but only when out of WASAPI or ASIO Mode.