The script available there: https://github.com/eoli3n/archiso-zfs makes it extremely easy to add ZFS support to any Arch ISO after it has booted. You can copy any standard ISO to a USB drive, boot off it, then run `curl -s https://raw.githubusercontent.com/eoli3n/archiso-zfs/master/... | bash` and you'll have ZFS support in a few seconds, without having anything to worry about.