I normally fly from the UK (out of schengen) to France (technically still in schengen). Without any issues by going through a customs airport. Some airfields require prior notifications a few hours before for customs officials to be notified (such that they would be able to organise coming to greet you).
I haven't seen any difference, whether going to or from Schengen countries, and into France over the last year or two.
I would contact the customs officials at an airport you are considering landing at (the French AIP print the local customs branch at all customs airports on the plates) and just check with them, tell them your plan and see what they say. It has very rarely been more than just announcing yourself, as you would for any other flight with the addition of sending an email to customs (occasionally they ask for 24 / 48 hours notice - so watch out! If they don't mention it - it might state "customs during hours of operation" whereby they have someone there all day long sipping strong coffee).
Top tip though - if you send them an email, quite a few custom branches have a tendency of not replying to English messages unless you ask them to confirm the reception of the email.
Hope this helps!
Alex