https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/release_notes/ocp-4-18-release-notes#ocp-4-18-known-issues_release-notes

I'm not sure what exactly is the "best-effort CPU Manager policy" in the 4.18 release notes' Known Issues section.
It says: "As a workaround, schedule a pod with a best-effort CPU Manager policy on the affected node." 
The CPU Manager only has none and static policies, so I suspect this might actually be referring to the best-effort QoS.