do you know if you can pass through raw disks as well? I.e. i see that it supports ZFS could i attach that pool within a vm and not directly to proxmox?
Proxmox's hosts controller does not require being on ZFS itself...you can have multiple drives and filesystems. If it were available to Proxmox and not passed through, it could be allocated only to a particular VM. In case that was your only end goal..