"German Refining Facility" in AVZ carbon footprint report, page-68

It is not only the margin, more sulphate also means per weight unit of lithium, less material to transport, ie a greener footprint.
And there is more... at this moment due to the transport limitations, the more lithium weight unit, the harder they can work the mine. In other words they can increase production.
As mentioned before, after start up and fine tuning the debottle necking of the entire process, from mine to customers occurs.