Same argument was applied at Sheffield City (EGSY) when it opened and was carrying scheduled commercial traffic from KLM, SN and BA C.
Nobody hit anything.
In the area generally, there is far less traffic than in the SE around the London area for Farnboro', Blackbush, etc where there are big biz jets around.
There may be more GA crossing class D space at EGNX (East Mids) North to South because of the bottleneck caused by the class D space there.
I recall Finningley was going to get (sorry, Doncaster) a radar service piped from the Claxby radar head and into John Lennon for approach control. Did this not happen?
(Waddington hrs are reduced but Doncaster is H24??)
h-r