I have two separate field groups that are set that overlap on a single page. For example, 1 field group shows on all pages, the second field group shows on all children pages. The following occurs while editing the featured image of the child page (which has both sets of fields displayed).
I am seeing the acf fields (in this case, it is a flexible content field) present under the meta data fields for the Featured Image. It is not a high priority, but could potentially confuse editors or content managers.
Thanks for all of your awesome work!