Have look on the Aerostitch website,they make a peak that will fit on any helmet that uses a visor.I've never seen one in the flesh,so would be interested to see it if you bought one!
I think the drag from the flipped up front would be more of a problem than the peak
But like most people I suspect I would open the visor
Can't imagine that it's much different from the Arai Tour except that in far off lands the locals can tell it's a person riding the bike a lot quicker, as opposed to a Stig. And they can see you smiling so they hopefully think your friendly and avoid the :