Hi @timm
I think you can use the Local JSON feature and then let your users sync the field groups. This page should give you more idea about it: https://www.advancedcustomfields.com/resources/synchronized-json/.
But please keep in mind if you allow your user to modify the field groups, it can cause issues in the future because they can change anything, even if they don’t know the usage of the changed options.
I hope this makes sense 🙂
