Dan Sodomsky of eCycle helped me design an intermediate drive idler for the Grasshopper 5R which allows the belt to be on the outside. This makes it much more convenient to take the bike apart for folding - one does not need to touch the chain at all. It is also a much simpler, smaller and lighter device as can be seen in the two views below:
The front view of the idler (belt side).
An underside view of the idler.