Did you ever resolve this? I have the same issue where I do not have access to /libs/granite/security/content/useradmin.html in our production and staging environments.

Thanks for the suggestion. I will probably just go that route. 

I have a requirement to provide an SPA like experience in a certain component and need access to some user group information after the page has been loaded based on user interaction.

I came across this article https://sling.apache.org/documentation/bundles/managing-users-and-groups-jackrabbit-usermanager.html on the Apache Sling site. This jackrabbit-usermanager bundle exposes REST interface to perform CRUD actions on users and groups. It doesn't seem like this bundle is include...