Instead of BOH how about OXF. As you are probably aware Varsity Express suspended operations yesterday. They had taken over 500 forward booking for the next few weeks on the EDI route and filled 135 seats with fare paying pax out of a total capacity of 190. Which is good for the first week of operations
Their Dash-8s would fit the route well and wouldn't be payload restricted during the summer like a J-31 or Q400 would be. Still, I'm not sure it would warrant a double daily service from PLH - at least to start with, which would mean adding an additional aircraft with relatively little utilisation, unless further routes were commenced which increases the risk.