It isn’t such good news from the French side of things who replied to an email I sent:
Hello,

Thank you for contacting the France Consular Service.
We wanted to inform you, in order to make your trip as smooth as possible, that all travel documents, such as plane tickets, reservations and visas must be in your legal name as it appears on your passport and your ID. If you must travel without proper identification, you can carry a note from your doctor explaining your transgender identity.
If your passport does not include a non-binary gender “X”, you can specify your gender identity to the border police officers in order to facilitate the control.