In the end I settled with only using the acf-json files (https://www.advancedcustomfields.com/resources/local-json/). In the hierarchy of ways that fields can be added, ACF prefers the acf-json files above the fields in the database.
I don’t do any synchronisation between environments at all anymore. The JSON files are being distributed to testing and live environments through git.
The whole ACF admin area is hidden on environments other then the local development environments. This way fields can only be added or edited on development environments, if this could also be done on other environments, the changes would be overwritten upon a git update.
