I've built quite a few distortion/OD circuits, but I've also played a MIG100 amp and to me few pedals go that way. It's quite dark sounding and very grainy (I also have a MIG50, which is quite bright in comparison), not what I would qualify as "high gain". the only one I can think of is the Green Citrus circuit (not that I've built everything, but I really like this one), really sounds like a "pushed too hard" amp... if you want to give it a try, I've got a few PCBs fabbed (without the Bosst control), and I will gladly offer you one (to thank you for all the great layouts/circuits), just drop me a PM.
here's good example of the sounds you can obtain so you can see if I am totally off topic: (zero processing, M160 in front of the cab, guitar is a baritone tele P90 neck pickup)
and a few clips with an optional cap selector switch (like the FAC orange control) guitar is a kramer alu neck, P94 neck pickup
https://soundcloud.com/cylens/lime-fac-guitar-low-gainhttps://soundcloud.com/cylens/lime-fac-guitar-high-gain