Confluence Admin Key feature VS content restriction

Hi devs!

It seems like Confluence Premium has this realtively new feature called Admin Key that allows admins to bypass the content restriction API entirely and from the look of it, it seems like a GUI level feature only for pages, at least for now.

The introduction of this feature raises a bit of concerns about the content restriction API, is the Admin Key feature also available, on either GUI or API level, for custom content as well? It seems like something that’s important to be documented because it might affect how developers would want to design their apps around the restriction API, but I can’t seem to find any documentation on that. Any clues?

Thanks in advance.