SDC rerouting worked like a charm for me. On my outbound I was able to change TPA-MIA-BOS to TPA-DFW-BOS. On my return, I found a phone agent who was willing to change my BOS-MIA-TPA to either BOS-DFW-TPA or BOS-SJU-MIA-TPA, however there was no availability. And I was booked in O.