On ZFS, I don't think there's any reason why it needs ECC more than any other filesystem [0].
[0] - https://jrs-s.net/2015/02/03/will-zfs-and-non-ecc-ram-kill-y...
[0] - https://jrs-s.net/2015/02/03/will-zfs-and-non-ecc-ram-kill-y...
"...We further demonstrate that ZFS is less resilient to memory corruption, which can lead to corrupt data being returned to applications or system crashes..." - https://research.cs.wisc.edu/wind/Publications/zfs-corruptio...
"Please Use ZFS With ECC Memory" - https://louwrentius.com/please-use-zfs-with-ecc-memory.html
...ie, ZFS is 'less resilient' in comparison to its robust disk fault handling, not that it's less resilient to memory corruption in comparison to other filesystems. The parent quotation above implies that ZFS is more sensitive to memory corruption than other fs but that is not claimed in the referenced paper.