Hi,
Since it seams that gamepad is still doesn't have vibration option, I'd ask if someone could create an addon to official plugin that would do that. Obviously, it won't work with all exporters, but if it could work at least with nwjs that would be ace. There is https://github.com/andrew/node-xbox-controller . Maybe you @rexrainbow could help since you're plugin wizz?
Cheers