Actually, you do not need to sync the field groups if you are using local json files. The field groups simply need to be in the right folder. You can delete the fields in the ACF admin and upload the json files. No one will be able to modify these fields on the site unless they sync them. Then you disable the ACF admin completely and they can’t sync them. The only play you edit them is on the dev site and then upload them when you’re ready.
