Purely for info, this is what ANEF, (the online platform for obtaining a new or renewal of a CdS) seeks for its lightest possible process - ie an EU citizen wanting to renew a permanent (sic) 10 year CdS.
All they want are some personal details, copy of passport, justificatif for the home address, ephoto and a declaration of honour that you haven’t been absent for more than two years. And that’s it! No charge, no language tests etc.
I defer, obviously, to those with real expertise like Kim, but I can’t help wondering whether this may serve as some form of future model for WARP card-type renewals…