If you get stopped with a satnav expect them to inspect the settings carefully. They're also talking about making road atlases that have speed camera sites marked on them illegal too. .
I'm back from my month's tour-du-France. I did see a remarkable increase in active policing and a massive increase in fixed-site cameras.
TomTom updated their app last year to comply with French law; removing camera positions and replacing them with "danger spot" positions. It works perfectly and every time TomTom warned me, sure enough there was a camera. I can't believe someone as international and established as TomTom would be doing this if it didn't fully comply with the current law. I certainly had no doubts about using it.
What did strike me is the new generation of cameras. The old one are very large and despite their size, and yellow edges, are actually quite difficult to see (especially at speed!) because they are battleship GREY. The new ones, presumably digital, are tiny. They are only about 1.5 m high and about 20 cm wide, and grey. They are impossible to see, they look like an anonymous post, without the help of TomTom or similar.
You were certainly unlucky to be stopped three times, I was ahem "making progress" and avoided being stopped, whether a postcard from France will be winging its way to me is yet to be seen