I've had one East/West transit approved by East Midlands and a second refused (claimed because could not detect my transponder).
I've had Luton transits approved - not following the standard routings via VRPs shown on charts - and on one occasion, when planning to route round the North / East corner, was offered a transit I had not requested. On the other hand when planning to enter/leave Luton's zone to land/depart Rush Green they do like a telephone call to approach first.