>>309121815
Not only for headpatting. 
>>bulky, heavy, lackluster single dimensional force feedback
Can be in all dimensions with three motors. 
>>on a controller that was designed to be as light and unobtrusive as possible
That is basically the one design issue to fight will. Make the wheels heaveir to save space, but then the controllers will be too heavy. Make the wheels bigger to save weight, then the controllers are to big. But such is live as an engineer. I will try to make it work at some point.