Yes BOH and EXT do over lap for the IT market
Anyone west of Poole/Weymouth/Dorchester would consider EXT (and BRS) for a package holiday and flights if BOH was not available.
Locals hate going up to LGW
Local Businessmen from Penzance to Dorset would consider EXT BRS NQY or SOU - or the one for them that has best links (train, motorway) and best flights ---
(Well, depending on the current Flymaybe debacle)
Does NQY have any IT or Sun flights? They used to have a PMI at one time...