Don't think an extension on the ext route to NQY would work but I am surprised we have not seen NQY-LCY launched Friday, Saturday and Monday for example by either BA or BE
You suggest that an airline dedicate an aeroplane to peak time flying to a borderline UK regional airport from a high cost business friendly airport like LCY, but need to consider what that aeroplane does for the rest of the week? If they won't maintain an existing (allegedly profitable) route like LCY-ABZ, what chance NQY?
EXT is screwed I suspect and DUB will follow as BE are trapped in a BA/EI/FR sandwich.