I have a couple of multisite WP installs. One of them is for a single company that has many sites for each branch office. All of the sites use the same theme. What I did was I created 2 themes. One of them is on a sub site where I maintain the ACF field groups. When I updated one of the groups it is saved into the theme’s acf-json folder. The other theme is used on the sites and in that theme I load the field groups from the management theme. This allows me to easily maintain and alter the field groups as needed while preventing the client from being able to access and change them. I did this because I knew that this company would likely be a long term client and I also knew that I would need to make changes as time went by. In this case the ACF JSON in Pro has saved me a lot of work when changes are needed.
