DFR would give you the answer to that straight away if you gave them a call but if you choose one preference and fail you can book another assessment day for another preference when you want.
I think finestkind was implying the ADFPSA being the PILOT selection agency, they are only concerned with your pilot preferences. If you have other non-pilot preferences you still have the case with DFR and you can pursue these preferences while waiting for a flight screening spot. Again, DFR would tell you this in one quick phone call.