Sounds more like modification of the existing Ernest Henry mill...

Sounds more like modification of the existing Ernest Henry mill and/or ore blending would be preferable for all, rather than building a brand new custom build greenfields plant right next to an existing hungry mill, especially with reasonably small orebodies.

Building anything new during a mineral boom is asking for permitting delays, cost over-runs and other inflationary stuff going on at the moment makes it a bit of a risk.