I created a test VM using VMWare Fusion 11.5 with VM Passthrough Enabled and two 20 GB disks. Despite choosing RAID1 and /dev/sda and /dev/sdb during installation my zpool only has /dev/sda. According to https://pve.proxmox.com/wiki/ZFS_on_Linux#_bootloader raid1 zfs for boot should be supported and I haven't run across anything on google or the forums that indicates what I might be doing wrong.