If the alternate current mode has been modified to be enabled, the config is stored inside the world data instead of the config folder which means deleting the world folder will also reset this mod's configuration back to defaults.

This means if you wanted to make a new world save then you would have to go inside the world folder and then delete the files from there whilst leaving both the main folder and the alternate current config intact which is not the ideal way of storing configs in first place.

The config is stored per-world by design. Enabling AC in one world should not enable it in all worlds (which is how early versions of the mod behaved). There are valid reason you may want to have it enabled only in a few specific worlds. Having the config in the world data also allows that world to be shared, and opened by other people with the correct AC settings.