EXT is Flybe's home base - dream on. BOH is being closed by BE - Jet2 did it for a while. Didn't last long. CWL is a thin route to say the least, but BE have it covered. SOU does well - its runway is likely the reason neither EZY nor FR are in town. ABZ is undergoing massive consolidation because of oil prices nosediving. INV would provide low numbers (as is served thoroughly by BE). NQY is a seasonal destination that is also thin from the north of Ireland.
So. Two things would need to happen. The first would be IAG deciding an airport stocked with EZY and FR (in some form) would be an attractive proposition. The second (after the very unlikely first) thing to happen would be the chaps in charge to decide all the established routes operated by BE would be financially viable for them to duplicate at BFS.
Seems unlikely.......