Good news, we've just released the oficial how-to for Native Pluggable Widgets.
It should work in a similar manner. Is it copied to your projects widget folder?
btw – Internally we also use the generator for native mobile widgets.
Next week we will release a how-to for building native widgets.
Hm, good chance that this is not implemented in the generator-mx-widget.
Firstly I’ve use the widget builder for native widgets and always have had it work just fine. Not sure what happened in your case. Here’s how to edit an existing widget:
Inside the file <widgetName>.xml, look inside the widget tag. You should see a property that says:
If that’s set correctly and you build the widget, it should be recognized as a native widget.