I was hoping to use this to enroll my daughter after our trip to Ireland in October as all of the airports we could complete the interview at are 3+ hours from us and appointments aren't available until the very end of the year, so doing it on an existing trip would be great. However, we are flying from DUB to PHL. I believe that you clear CBP in DUB so does that mean we will be unable to take advantage of this in PHL? Thanks!