Hey @Alwin
Site Hardening scans the sites on each sync and on-demand from the Child Site’s Hardening page.
Right now, there is no option to completely disable the entire page.
However, you can disable the checks on sync from the Advanced Settings page (/wp-admin/admin.php?page=SettingsAdvanced):
Additionally, you can disable individual checks with a filter. You can find more info in this discussion: Can you Disable Certain Security Checks? - #4 by xyzulu