We currently have a large deployment of Firefox ESR with a local configuration file that, among other things, disables auto updates. We're looking at enabling auto-update using GPO, and then where necessary using GPO to disable for specific machines. Since we're using a local JSON file currently, does anyone know if the GPO would override the local JSON file? Or do we need to modify/delete the local JSON file before the GPO will be effective?

If we just switch to GPO, we'll end up with the following settings: JSON - Updates disabled GPO - Updates enabled