As I recall from local airspace user groups a while ago, the airspace above Scampton is a prized asset. I would imagine Durham Tees Valley would not be happy about the establishment of a D313 type area up to 9500’ on their doorstep - Doncaster were already trying to grab a piece of 313 but it has grandfather rights! Wittering would appear to intrude on the Sibson PJE reservation so wouldn’t work, and the Reds complained about the transit time from Cranwell to 313 back in the day....
The (last) plan for Waddington involved a separate enclave on the ‘Vulcan’ side of the airfield, the catch being the need for a separate entrance from the A15 which was going to cost a lot. However, I think the airspace issues might mean that Waddington gets them.....