In case of we've got the different user account from JIRA and Confluence administrator, the following scenario is causing some friction:

On JIRA ServiceDesk linking to a Confluence space for the knowledge base, with a JIRA project administrator that is a normal Confluence user without any space administrator privileges or system administrator privileges, by changing the Viewing access from "Only licensed users who have access to the space" to "All active users and customers can access the knowledge base without a Confluence license.", it gives the no Confluence administrator user the privileges to:

1. give the "Use Confluence" privileges to all unlicensed Confluence user, which requires the Confluence system administrator privileges.
2. give the "View page" Permission to the selected spaces to all unlicensed Confluence user, which requires either the space administrator privilege or the Confluence system administrator privileges.

It should be better to ask the Project administrator to be the Confluence space administrator privileges to avoid this friction.