The parking size int the AFCAD is not relevant, if there's a GSX customization file, which will take precedence. And, the GSX customization file we provided with the scenery (kclt-fsdt.ini), list a wingspan of 65.0 meters, so that's the only parameter that counts.
It may not be all that relevant for the user and his aircraft but what about the AI that doesn't use GSX for parking?