Okay, I spent an afternoon with a bag of M lenses, my M8 and the Nokton 35mm f1.2, and a 2 mm Allen wrench.
Seems like my M8 was a touch out of alignment at infinity.
It is now adjusted, and the Nokton 35/1.2 is spot-on at infinity.
Here is an earlier shot from the 35/1.2
Vick