COPR uses this option. IIRC it's used to fetch only partial metadata.
[dnf.git]$ git grep enabled_metadata | wc -l 0 [dnf-plugins-core.git]$ git grep enabled_metadata | wc -l 0
This bug appears to have been reported against 'rawhide' during the Fedora 25 development cycle. Changing version to '25'.
*** Bug 1357797 has been marked as a duplicate of this bug. ***
https://github.com/rpm-software-management/dnf/pull/548