Are there any Coastal Command types in the virtual crew room who could offer an opinion?
The in-flight refuelling systems used as late as 1950 still relied on the looped hose and grapnel technique. Trying to do this over the North Atlantic at night does not commend itself. Granted, under wartime pressure there may have been faster development, but that said, proposals to use in-flight refuelling for Tiger force still relied on hose and grapnel,
As far as using the system to extend into the North Atlantic gap is concerned, the nav aids available at the time were not up to guaranteeing a rendezvous over the sea. The only system which might have worked would be for a tanker and a maritime aircraft to fly west in formation, do the refuelling, probably in daylight, and then have the maritime aircraft come off task with enough fuel to recover to base without a further refuel. With all the complication, plus the likelihood of the two losing contact outbound in bad weather, it does not seem practical.