As I posted, you should look at some of the other solutions you can find in the search results that I linked above. I’m not going to repeat everything that was covered in previous topics here.
I don’t use this in any way for the reason I stated. When it comes to field groups of this nature I never want anyone to be able to edit them and only edit them where I do development. There is also at least one plugin that includes this functionality.
There are other options.
1) Using child themes of your main theme on sub sites and adding a load point
https://www.advancedcustomfields.com/resources/local-json/
2) Since this is multisite you can add a load point to anywhere in any other theme without necessary having parent/child themes.
