No problems with the open belts - I think ppl have been running this way for a while w/o incident - it's cool to see the machine at work. Harley folk freak out b/c their drive belt is exposed too. I suggest not to wear boxers and cargo shorts though... Ouch!
common sense left me for a minute, and I was wiping my fairings down with the motor running and the rag almost got caught in the belts, which would have been fatal to the motor. To those who think, "eh, I'll just be extra careful," Don't do it!!
One guy on here sold his Leggero belt covers because he bent a valve doing this.