I top out my bike regularly.
The first turn going up the back side of Ortega Hwy (Little road near my neck of the woods) is a posted, 50mph, I think. could be lower.
well... I usually am at 105-115 mph (depending on my mood) & my bike is as stable as can be.
Next set of turns (35 posted) I'm at 80-90mph. still, no hint of head shake.
First straight, 125-130 mph, carrying the front slightly out of a mild left, still, no hint of needing a stabilizer.
Tires, tire pressure, suspension set up, & body position will cure a lot more than a stabilizer can compensate for on a 919.
But...then again, it could just be me.