If a large commercial aircraft is operating in Class G airspace, it might only have protection once it reaches the ATZ.. There seems to be an argument for the airlines flying through Class G airspace to airports such as Doncaster to consider making a visual approach, and to make a visual circuit as well. (Yes, I appreciate that they would most likely be outside the ATZ).
Thomsonfly seem to like to make 10nm straight-in approaches, or at least procedural approaches, and never adapt to visual flying. They are probably not allowed to, because some bright spark has written into the OM that is it forbidden.
If this is so, it's a pity, because aircraft from Sandtoft, Retford etc will most likely keep clear of DSA up to 4 or 5 nm out, but might well cross an approach path at 6 or 7 nm. Maybe they shouldn't, but they might.
If the B737 joined downwind, and conducted a visual circuit (when wx permitted) it would be in a safer environment than if it carried out a long final approach.
What I am saying is that the airlines could help themselves if they were a bit more flexible.