PH-UKU
It may help other readers to visit the following site for clarification of the different classes of airspace in the UK:
CLASSES OF UK AIRSPACE
I presume the routes to which you primarily refer are those which link the 'minor' civilian aerodromes (Aberdeen/ Newcastle/ Teesside/ Norwich) up and down the east coast of the UK? I was not aware that they had a different classification from the overall Class G.
As a military controller, I am concerned with the east coast routes; in particular, Operational Trg Area (OTA) C to the north of Newcastle is bisected by the Aberdeen-Newcastle/Teesside link route.
Notwithstanding the formation of the Southern and Central Managed Danger Areas (MDAs), clearly there continues to be a requirement for military aircrews to practise tactical flying overland. This flying is not restricted to low-level work, but also involves air-to-air practice engagements at medium and low level.
In addition, the move of 56 Sqn to Leuchars has undoubtedly increased the volume of activity immediately to the east of the airfield, between the coast and western edge of the Central MDAs (the so-called 'stubs').
From a personal perspective, I can assure you that potentially conflicting traffic is always called-in to crews iaw the service they are under (usually RIS/FIS). Where particularly complex sorties are planned, I endeavour to let the civilian controllers know in advance, but it is not always possible, neither are they always terribly interested. Subsequently, I will try to push activity to one side (usually the west in OTA C) of the link route, but the military crews often require a degree of tactical freedom which precludes the maintenance of standard separation against other air traffic. If undertaking ACT, I will use a 'KNOCK-IT-OFF' call if I consider FS is at risk.
I have often seen ac descending into Newcastle straight towards a turning fight, even when apparently under RAS - I too would be bothered about this in your shoes; clearly the commercial imperative requires timetables to be kept to!
I have heard it suggested that the option always exists for the 'B737s, Emb 145s doing 430kts plus' to route via the airways structure, but that ignores the fact that not all the aerodromes are linked by airways. I also think it would be naiive to expect Class G to be avoided by commercial traffic simply because it is being used by military traffic.
At the end of the day, I suspect most FJ aircrew will seek a radar service only in IMC, and that this will be in response to the met rather than the requirement to cross or operate within Class F/G airspace. I await, with interest, the responses of my breveted colleagues.
Edited in the interests of clarity!