C1 Co the two classes don't mean much to me. What I do know is that the weight is decisive, the drone weighs 248g so I can fly almost anywhere. From 250g has more regulations. That's all I know.
The DJI Mini 3 Pro (not the "normal" Mini 3) can be provided with a subsequent C1 label if it fulfils certain requirements (e.g. firmware update, application). - The DJI Mini 3 (standard) is not officially C1 classified as it weighs less than 250 g - it can be considered "C0 compliant" if it has an official C0 label. - DJI has offered a C1 upgrade for some models (e.g. Mini 3 Pro or Air 2S), but not for all.