HI GQ, I'm not really experienced enough to enter into the technical arguments here but I'm amazed at the difference in training between you 'down the road' as it were and what we do here, which in theory you would think would be broadly similar. I've honestly never heard of a fuel circle, we are taught to lean out at whatever altitude we are at and I personally always take off with full tanks, in fact we always keep the a/c tanks full for condensation prevention. You can never, in my opinion, have too much fuel. Obviously weight and balance considered and bearing in mind I don't fly jumbo jets.
Incidentally I was doing some NDB approaches at your place today, (it's free after all...:-) after ringing your tower mob and being assured they could fit me in at a specific time. I finished up doing four flogs round the holding pattern (in clag with a 30kt wind) before I got clearance. Total time to fly the 8nm to your place and the 8 nm back to mine was 1:30.....it would have been cheaper to go to Donny and pay my £4.50.