Any reason why you could not negotiate to fly on a Special VFR clearance to leave the Bristol CTR? For example, in SW'ly wind conditions, you could guarantee to remain within a sector that could, given the will, be deemed separated from runway 27 approach.
Go and talk to the ATC manager, be willing to be flexible, and have a few facts available - e.g. how many times in the last year have you been unable to launch under VFR because of the current Bristol reported visibility? (Invite him for a flight, to see the operation from your viewpoint).
We have special written agreements with Bristol over flying in their zone. I was just interested in the AIC and the interpretation of it, and it seems that there is much debate over it and the purpose of what it is trying to achieve!