There was, in fact, a polarity. It was incredibly easy to install. There was a machined aluminum spacer which, after looking at the existing bar end, obviously went on one way. Maybe it flips over for other fitments (YZF-R1, YZF-R6). There are two friction washers which, according to a photo, both go on the stack but it becomes clear that you just select one thickness depending on the desired spacing. I chose the thin one so I could back the lock way off the friction point to avoid accidentally engaging it.
I tried the lock out this morning on a limited-access state highway and then on the interstate. It engages easily and has a wide range of workable friction zone. It holds without loosening from vibration and is easily over ridden either direction by advancing or retarding the throttle. It quickly and easily releases completely. My fat hand didn't tend to try to actuate it.