It’s getting there.
As of February, you can now install zfs on your Qubes system natively from the repos. This should be all you need to install (I have not tested): qubes-dom0-update zfs zfs-dkms . From there create your zpool and then designate it as a qubes pool with qvm-pool.
On a fresh install, I recommend not migrating anything, but creating the smallest possible initial pool on lvm, where only your sys-qubes will live, and then make a big zfs pool for everything you actually care about (set it to be default pool).