The whole reason to do this is to not edit them on the sub sites. All field groups added this way should be accessible to anything that needs them. The field groups exist the same as they would exist if loaded from the DB. The only difference is where they are loaded from. If there is some code that cannot access them you’d need to give me more details on this because that should not be the case. If other plugins cannot access the field it’s likely because they are not doing it properly.
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