If you want the minimum distance behind the toilet, you need to buy the 14" Unifit adapter as a separate part and no, there's no credit for the 12" one that comes in the box. You might be able to use a right-angle stop to get the water supply over far enough, and that might mean only replacing the stop, but it may require you to move the whole thing over. The position in the spec sheet is the 'ideal' position, it will work closer, but I don't think it will make it at 4". The cost to move the supply depends - it could be fairly easy, less than 1/2-hour or so, maybe less, maybe more. Depends on the labor rate at your location how much that is.