I'm wondering if add-ons for xenforo can be developed using different framework; than the traditional approach. That is, setup an API for xenforo first and then use different frameworks out there (say CakePHP) to develop add ons for xenforo? What are the drawbacks of this way of developing add-on? I can imagine that this would add the additional burden of matching the UI of the add-on with that of the site. What else?