I don't know if I'm understanding your question, but ZFS actively corrects data on disk when it finds a checksum error [0]. Those checksum errors can be found when accessing that data, or doing a 'scrub' action that scans the whole volume to check integrity.
ZFS supports self healing, you do not have scrub, it will be corrected during a bad read as long you have a copy. Metadata has 2 copies by default for additional safety for a single disk.
reply