Additionally, the refind_linux.conf mentioned in the README.md -
"Boot Default BE" "ro quiet loglevel=0 timeout=0 root=zfsbootmenu:POOL= spl_hostid="
"Select BE" "ro quiet loglevel=0 timeout=-1 root=zfsbootmenu:POOL= spl_hostid="
is very different from the config mentioned here -
"Boot default" "zbm.prefer=zroot ro quiet loglevel=0 zbm.skip"
"Boot to menu" "zbm.prefer=zroot ro quiet loglevel=0 zbm.show"