I'm surprised no one mentioned my one thought: PARKING BRAKE!! Unlike most ICE bikes, which you can leave in gear to keep it from rolling, there is nothing to prevent the Zero (or any electric bike I can think of) from rolling off the sidestand if parked on a decline. Even CVT-equipped scooters have a parking brake to prevent that from happening.
Best solution would be to copy BMW's idea of integrating the parking brake into the sidestand. With my C650GT, once the sidestand is down, you can't roll the scooter anywhere. Unlike my old TMAX (where you had to remember to set the parking brake), it's all "automatic."