@kedara Could directly run the actual ZFS scrub script on boot via "crontab(5)" ...
@reboot -n sleep 134 && /etc/periodic/daily/800.scrub-zfs
... with "daily_scrub_zfs_enable"d (
preferable would be to refactor the part for the "case" of "[Yy][Ee][Ss]" in its own script in order to not have to rely on extra moving part).