But without the added APD tax, we may have held on to our peak Puerto Plata, Cancun and Sanford. BFS would also look more appealing to help reinstate the lost Toronto link, after over 20 connsecutive years of service! Many of the winter routes I'd guess would be marginal at best, BCN, FCO, EWR and would greatly benefit from the reduction of the APD.
And however unlikely, BFS management have specifically mentioned Dubai, and with a more level playing field, I'd say this would help the cause, no matter how small seemingly insignificant.
As for people from Northern Ireland not using DUB to gain flights to the UK mainland, I think you'd be surprised. Those too connecting to long-haul may well see a financial benefit for using DUB via Europe, that who otherwise would've used EI/BD via LHR, especially being charged twice.
I'm flying BHD-LHR-AUH DXB-LHR-BHD in December, and was shocked at the amount of tax compared to the fare, phenomenal. Three flights in the trip departing UK airports!!