I wanted to update this with my experience as the info here helped me get my MT7s working after much messing around.
My buddy (who is mechanically minded and I trust was suitably gentle with them) bought them, and had leaking issues from brand new. Both sets were leaking from the lines, the front one from the factory (the rear I believe was internally routed so hard to know if it is a factory or installation issue). Magura provided him good warranty service and sent a new set of lines. He got tired of messing with them and went to the xtr 4 pistons, and sold me the mt7s at a loss.
I installed them on my SB 150 with the new lines being very careful to follow the torque and installation instructions. I could get them to about 60% of the lever firmness I would expect, but they were in consistent and I kept losing brakes on rides. It seemed like the system was sealed when the levers were adjusted horizontally in the bleeding position, but had a slight air leak when tilted to riding position. I tried bleeding them multiple times and had a friend who is a mechanic try as well with no luck.
I read about using shimano levers, and my friend had an old tektro lever (which uses mineral oil) around which we tried. It worked perfectly, isolating the issue to the lever. I pulled the pin on some current Gen non-servowave xtr m9100 levers. We installed the xtr levers with the magura hydraulic line bits, and now the brakes seem amazing. Got the xtr levers for $82 cad each off bikeinn.com, which I read many bad reviews of, but had no issues dealing with them.
-The levers are very fragile and over complicated. Made of plastic with many more seals than are necessary. For example, two plastic on plastic bleed ports on one lever? That’s a recipe for leaking. I would not trust these levers for any extended trip away from the ability to repair them based on my experience.
-I have little trust for the magura lines base on the leaking issues with the original lines. I will swap mine out for Shimano lines and fittings next time I feel like messing with brakes (which will be a long time from now).
-These are not a good set of brakes to buy used from anyone, unless it is just for the calipers and rotors.
-The Magura calipers are a very nice design. I like the magnetic pad holding feature and the one piece design. Using thicker rotors for heat dissipation seems logical to me, and magura makes 220mm rotors which I may try in front.
-Combined with the shimano levers the initial impression is they seem to be a very nice brake and a much more reliable system. I can update further once I have some miles on them.