I am sorry but not sure what is 'lagging'? If you would like to see the scan log then you can view the logs from the location (C:\ProgramData\McAfee\DesktopProtection).
OnAccessScanLog is for OAS scan.
OnDemandScanLog is for ODS scan.
If you are reffering 'lagging' as performance degradation or computer hang situation during specific duration- please check the process(s) adding to this. You may use process explorer or process monitor tool to see what is happening during that time. It should give some clue.
Assuming Virusscan enterprise (VSE) is adding to this issue, check if there are multiple Scan tasks are running simultaniously. Also, check the Scan configuration for Scan types. Like archive scan, Network scan, scan on read and write etc.
Refet to VirusScan Enterprise 8.8 Best Practices Guide: https://kc.mcafee.com/corporate/index?page=content&id=PD22940