Nice. Brian you get extra credit for reading a manual for a bike you don't even own.
I have to admit that it took me a long time to really look at the FX manual, or manuals before 2013, but there's interesting stuff in there if you have a relaxed eye.
The 2017 Owners Manuals are posted now.
One thing I noticed on page 3.21 is a parking brake lever on the left handle controls. It's described conditionally, and I haven't noticed one in photos or one in person look around at the bike. Keep an eye out for this!
I misread the diagram! It's on the inside of the right handlebar and the lever swings outward to cover the mode switch, basically a nicety to keep you from trying to use the throttle while the lever is engaged.
Page 6.14 lists maintenance for the parking brake, so it's easy to figure out how it works:
The lever pulls some calipers against the rear brake disc using the cable. The maintenance is just to adjust cable tension like a clutch cable needs (probably worth a tiny bit of cable lubricant once a year as well). So, I think it avoids stress on the hydraulic system.