We had a long discussion on class G airspace and the mix of IFR and non transponding GA. There is a small risk of collision and hence Doncaster has got its controlled airspace. No way are they going to risk a collision between a glider and a 737.
Gliders, balloons do not have a level of control over their direction or levels so dont count on either being allowed in that space unless there is a big envelope of time between departures. Then we have the problem of NO transponder.
I can see more chunks of airspace being controlled in the future unless ATC can be sure of where someone is and have communication with them.
Pace