The challenge is that HM-SMR drives require zoned block commands. libzbc exists but you’d need to get your hands on a drive or firmware that supports it, as well as making sure you don’t break any NDAs in the process.
But pointing back to a couple old posts of mine that aren’t NDA-specific material:
Rewriting ZFS to handle HM-SMR would be a massive undertaking, and the improvements in areal density brought on by energy-assisted recording have mitigated the need somewhat.
