Not sure what day of the week you are looking to travel, but looked at a couple of random days in June and July and there is a British Airways flight from LBR-BHD which will get into Belfast at 8.30am. It also looks like BA is cheaper than Aer Lingus.
Now that scope clauses and other agreements are being discraded in this brave new world, expect to see a harmonisation of scheduling, particually between IAG companies such as EI and BA across the sea. Does it really make sense to have night stopping crews at each end. LHR to BHD/DUB come to mind with a 2 airline/single offering approach.