Am I missing something? All Leaf models have the passenger airbag off warning light/VSP off light on the very bottom of the dash, underneath the HVAC controls. Therefore the switch is compatible with all Leafs and uses the factory button. That's like, the point.
The request was to use one of the blanks (probably on the left side of the steering wheel) to implement a separate switch for control of the VSP.
I like this option as well to keep the way the SRS/VSP display works true to factory original.