Aero Mad,
Keeping the airport open may be one thing ... trying to operate, quote, "jets" in and out of there is something quite different.
That said, back in the day, 'we' did get jet movements thru PLH ... they had "Royal Navy" printed on the side of them!
About the largest thing in/out of PLH is an ATR42/72, AF might have access to some of these but KLM do not operate any turbo-prop aircraft and a Fokker 70 certainly ain't operating thru PLH anytime soon.
And just look at how AF & KL have committed to EXT, that can take jets, KL are nowhere to be seen and FlyBe operate a thrice weekly, not thrice daily, AF codeshare to/from, of all places, ORY.
Does Southway housing estate fall under the category "geographically"? PLH might be able for a marginmal extension but that is it, marginal and still many an aircraft type will be opting, based on performance, for EXT and NQY.