Most of the time on mine so far the burn off is enough to only create a light oil filming inside the muffler area. The stock Akra muffler really showed this issue alot but the spark muffler I have on there now decease the residual build up and its more just blackish / oily touch.
If you ride the M1000 like it was intended at high RPM's and keep a really good burning fuel in the bike, it will last at least 20000 miles with no issues. If you ride it like commuting to work or coffee stop shopping, you are going to build carbon more based on the oil issue passing the rings than a bad tune in the ECU.
The sole purpose of the 2 ring concept is for less friction, and lighter rotational weight. The 2 ring piston has one compression ring (instead of two) and one oil ring. 2 ring pistons (four stroke) have less drag and can help performance, but, another issue found, some must be replaced more frequently. They do cause less wear on the cylinder too since it has always been found the oil control rings are scrapers and create the wear.
Wisco has been making performance pistons since I can remember building engines back in the 80's. Even in 2 strokes where 2 ring piston was the normal, Wisco made 1 ring pistons for those replacements in the high performance use market.
I am happy to own my M1000RR, but, the way this bike has shown its 'street' issues, I am very happy I also own the S1000RR K67 so I can put more miles on it and less wear and tear of my M1000.