I've never understood the logic of cancelling SAR in the circuit - yep it's legal, and convenient at places like BTI - but you're officially saying "yep you can forget about me now" just before commencing the (second) most dangerous phase of flight.
And there's a disturbing increase in "request return code" followed by "no joy HF" around the islands, meaning "I can't be bothered getting new traffic information after my 5 minute turnaround, even though I'm required to".