At the airport I just sat down anyway. Someone called security and I eventually convinced them to go away by showing the receipt for the antigen test I had done an hour prior (flying to Switzerland).
@verretor Apparently France's scheme for recognizing foreign vaccination _requires_ you to have a return flight booked. I often show up in countries without even having accommodation booked...
I probably could have convinced the security guard to let me stay with Canadian and maybe US (CDC) "proof" of vaccination. But pretty lol that the staff don't know the rules at an airport.