Hi Andy,
There was a
discussion about Dinard last year. Turned out to be fine in the end.
As everybody has said, there's no getting away from the Customs requirement.
I think that the one area where the combination of France and the Channel Islands does cut out a layer of bureaucracy is with Special Branch. If you go to or from the CI directly from the UK then Special Branch want to know about it, whereas if you go to France first you are at liberty to carry on Jersey or wherever without informing them, since by then it is none of their business.
I have never fully understood quite why Special Branch want to know about CI visits. Perhaps it is to catch people taking ill-gotten gains to and fro who are too stupid to go via France and avoid the scrutiny!
BTW, another pleasant little spot in the area is Avranches, close to Le Mont St Michel. As an Australian you will particularly appreciate the flock of sheep which live on the field. I had to do a low approach and go-around on my visit last month to clear the runway before landing!