The "explicit backlog" feature has been released since a while and is considered stable enough to be generally available.
It still requires feedback before completely replace the historical backlog management hence:
- The switch should be available to any project administrator, "Lab mode" or not
- The text should be changed to:
"Explicit backlog allows to select item per item, what goes in Scrum top backlog. See documentation" with a link to full description of the feature.