To the surprise of no-one here, WD SMR drives are a cause for concern…
https://www.heise.de/en/news/WD-to-investigate-problems-with-older-SMR-hard-drives-10872057.html
The treat (sort of 
):
Trust and reliability are the foundation of everything we do at Western Digital.
The silly thing about this, is that ZFS was specifically designed to detect and potentially correct, (if redundancy is available), mis-writes or mis-reads of disk sectors.
This is why ZFS checksums are not part of the sector, (like 520 or 4,104 byte DIF sector format). Such checksums would not detect wrong sectors, (though 4 bytes in the DIF can be used for the lower 4 bytes of the LBA).
Yet, WD Red SMRs have proven to be so less suitable for ZFS, (because of SMR delays and fragmentation), that you should not use ZFS on WD Red SMR drives.
Note: DIF - Data Integrity Field
