Am surprised no one has mentioned BHX. Route performed well when flown by Loganair for Flybe. Think it would still work given the reduction in frequency and seats on BHX-EDI and ABZ after the Flybe collapse. Maybe Loganair don't want to dilute their ABZ route in this Covid world, demand was very different when BE flew all three but in long term BHX-DND could work very well.