The type of muffler you're running, and the fuel mapping, can have an effect on vibration as well.
Most, but not all bikes don't need to be "geared down". <Usually, that's just stupid.
My carbureted 900RR, which is mostly the same engine, as your 919, is really smooth.
After I rejetted my little 599, and put a -2t sprocket on back, that bike, which has a nasty rep for being buzzy, which they are in stock trim; turned out to be quite smooth.