I'd say it may be a bit of de-risking through diversifying...

I'd say it may be a bit of de-risking through diversifying suppliers perhaps Sevo? Albeit they are not long contracts but I think it just mitigates Mitsui's risk should one the SoP producers fall over. A few bad cyclones could see a hiccup in supply if it was just through one supplier. Given Mitsui are into Salt as well in WA, they seemed to have taken the same approach there. All just my speculation of course.

EE