I'm really sorry if this has already been answered, because I know it is annoying, I thought it had been but having searched again through 103 posts I am not finding it.
Do we know precisely what they mean by "traducteur agréé" (for birth certificates) - presumably less than "assermenté", but what proof of competence, if any, is required?
As a translator autopreneur for some years myself, I have done many documents for clients - for mairie, préfecture, even courts, and although I have never pretended any status other than my logo and my SIREN nothing has ever been rejected. I am reluctant, however, to try this for my own Nationality application, with the attendant risk of it being bounced back for this reason after a further 10 months' delay.
Better still, can anyone supply the details for a good translator who has already done some of these applications. I am in Ariège, although that scarcely matters when documents can be exchanged by post or electronically.