Loyalty: In addition to Male and Female, “Non-binary” is included as a gender option on Flying Blue profiles. “Other” is included as a gender option when adding a passport to a Flying Blue profile.
Booking: When booking a flight, Title is a required field, and the only options are Mr, Mrs, Miss, and Ms.
Check-in: I have not yet attempted check-in with a gender X passport on Air France.
Let Me X Plane 