Not sure if it was mentioned but instead of passing the sata device into the VM you could just mount a dataset into you VM and treat it like a real ZFS pool. Have a look at Is it possible to mount nested ZFS datasets from within a container? which explains what I mean by that.
Basically leave the core disk managment to your Incus host and just use storage pools in your container, applications and VMs. Puts a pretty clear line on responsibilities. Work pretty well in my installations with less complexity.