Follow the Manual's guidance -- but realize the guidance is very general and incomplete, consisting of basically rpm vs. mileage limits.
The most important thing in my experience with BMWs is to not "baby" the motor. That does NOT mean massively thrashing it, drag race style.
What it does mean is to vary the throttle position (and hence the load on the engine) a LOT. One of your objectives should be to frequently generate relatively high combustion chamber pressure so that the gas pressure will get behind the top piston ring to push is radially outward to scrub against the cylinder wall. This will accelerate ring seating and shorten the break-in period. Just droning down the road at a constant throttle position doesn't generate much pressure in the chamber (surprisingly little fuel/air is required to just maintain a steady speed, so opening the throttle to pack more air/fuel in is needed to reach good ring-scrubbing pressures).
EDIT: I went back and read the Rider's Manual break-in guidance -- it basically says what I said above -- vary, stay off constant speed highways, lots of hills, etc.
FWIW, my observations of a bunch of boxers and flying bricks over the years is consistent with this -- firmly run-in bikes would stop using any appreciable oil within ~6K miles (indicating good ring seating), while babied engines would take upwards of 20K miles before oil consumption started tapering off (if ever). The babied bikes tended to have more carbon deposits in the combustion chambers (due to the oil being drawn up past the un-fully-seated rings and being burned in the chamber), resulting in more frequent pinging issues.
HTH!
Mark