Multiple Developers in Essentials

Essentials 4.2 HTML5 2.3

All of the security information I can find relates to restricting access to elements within a viewer for a given site.  Is there any way to restrict which Sites within a single named  instance of Essentials Manager that a particular developer can see and access?

Our concern is that any developer with access to an instance of Geocortex Manager can access/edit/delete any site within the instance.

Other than creating a separate named instance, and an associated Windows User Group with access to the instance, is there any way to restrict a developer's access to any Site in an instance?