change ['/sbin/zpool', 'list', '-pH'] to ['/etc/snmp/zfs_get.sh'] in /etc/snmp/zfs-linux
Now close out /etc/snmp/zfs_get.sh and LibreNMS should now show what you need after 10-15mins. There is no warranty and I take no responsibility if anything happens. I'm not 100% sure that this prints everything 100% as it should, but it seems to make my graphs display data.