I just rode it like normal from day one. Changed the oil as spec'ed at 600 miles, there was some obvious fine silvery stuff in it that had made it through the oil filter but no different from any other new Japanese bike I've broken in, regardless of the method. I didn't bang it off the rev limiter or anything like that, but I definitely didn't baby it, I was commuting to work and back the next day which involved both some high speed 75mph travel and lots of 25mph lane splitting to get through the traffic jams. My take on it is that modern engines basically come pre-broke-in from the factory because they have to pass emissions the moment they hit the dealer floor (especially true of Kawasaki engines with their coated cylinders), the gearsets are the most likely source of any metal and they don't really care whether you're revving at 4,000 rpm or 8,000 rpm.
So why the break-in advice in the owner's manual? Basically, they're trying to keep new motorcycle owners from crashing the bike right off the showroom floor. But I've been riding motorcycles for over 40 years, I've never followed that advice and I've never had a motorcycle die on me because of it. I've had a motorcycle die from neglect (forgot to check the valves, sucked a valve, ponged the piston, engine full of metal shards with obvious damage to bearings and gears, gave up on it as a lost cause, I was 14 years old at the time so how was I supposed to know you had to adjust the valves lol), the rest just kept running until 60,000 miles or so when I sold them for a few dollars (still running well, still not burning any oil) and moved on to my next bike.
2018 Versys-X 300 ABS. Former bikes: 1983 Honda FT500 Ascot, 1985 Honda XL-350, 2001 Kawasaki KLR-650, 2003 Kawasaki Concours, 2008 Suzuki V-Strom 650.