What if FR have attained a couple of slots at LGW, and they 'have' to use at least one at a Belfast airport. I don't think BFS is going to encourage a LGW/BFS operation for obvious reasons. So they start a one flight per day DUB/LGW/BHd for 3 years and withdraw with a golden slot to use elsewhere!!!
I cannot see BE operating their full program at BFS, maybe they could base a couple of aircraft at BFS to utilise their aircraft for a longer program each day. The last flight out of LCY to GLA is 20.30 45 mins after BHD. 45 mins later is very good for business day trips, give them another edge over BA.