Get Leica M Monochrom Typ 246 at B&H Photo.
See my previous update.
Update 5 Oct: I received a response from Leica. Leica tells me that a firmware update is on track to be released that will address the issue.
In brief—back in early June, Leica contacted me about the issue, and I provided a DNG to Leica, one of many with the spots. I received a brief note from Leica as follows:
We have found the root cause and plan to make a firmware update that avoids this effect.
I don’t own the Leica M Monochrome Typ 246 and as I’ve said, I think that both the Canon 5DS R is a better monochrome camera than the MM246. As well, the Sony A7R II is a better monochrome camera than the MM246.