Update to my earlier post:
A while ago I had a test flight which systematically CTDed.
Strangely, that went away for a while : https://forums.flightsimulator.com/t/lfmn-nice-to-lfmd-mandelieu-ctd/441529/23?u=calitfipst
So I retried it tonight and twice in a row had the CTD again, same place, same time into the flight. I checked that the Capture One dll was indeed loaded into my flightsimulator process both times.
Renamed the dll, checked it was not loaded in my process, and had the same flight without CTD. Maybe one flight is not enough to confirm this is conclusive, will continue testing when I have time.
Why it it always happens in the same place, is still a big mystery to me.