France ... has a particularly rigourous procedure for GA arrivals and departures.
You are talking about the France which is just south of England I assume?
The one where I've been asked for my passport twice in the last dozen visits by air? The one where I've never been asked for aircraft documentation at all? I always carry it all, and fascinating reading it is too, what with all the nice CAA stamps and everything, but so far I've yet to find a Gendarme who was bored enough to want to read it.
I haven't entered France through very many airfields yet, but so far none of Cherbourg, Troyes, Deauville or Le Touquet could be accused of anything approaching rigour. A flight plan seems to be about the only thing that anyone is really bothered about for 90% of the time.