“Hanging off the bike?”
I often see riders taking this to an extreme, more posing than useful. Two things happen when you get off the bike too far so that it makes for a dangerous riding environment. Once you are hanging way off the seat, any future direction change is going to happen only once you have returned to the saddle. Now that could take a split second, but that is the split second that may make avoiding a riding issue impossible. Only very serious riders and serious speeds are capable of making use of this extreme riding technique.
Another downside to hanging way off is that when you wish to return to the saddle, most of us pull ourselves up using our arms. Now what are they attached to? You got it, the handlebars - also attached to the forks and the front tire. What is going to be the effect? You got it, unplanned counter-steering and a corresponding change of direction with potential loss of front-end traction.
Everything we do on a motorcycle has an effect and some effects are more than just a compromise of good results. Some are truly deadly. Never stop thinking about why you are taking an action while riding. Everything has an effect and consequences. Make sure you are aware of what you are inviting to sit with you at the table.
That behavior is for the track and even then only useful to the most skilled and advanced riders who race. In forty years of riding I have never met anyone who could ride at those speeds on the street who is still riding today. Hanging way off on the street is like putting $5000 worth of wheels on your Chevette - it looks obvious and does not make life better. If you are riding like that on the street, something is going to give - and there will be tears.