So then we get to the other source of optimisation scarcely...

So then we get to the other source of optimisation scarcely discussed. Getting the higher grade material to the plant quicker to get cash flow earlier and increase the NPV and share price. I asked Greg Myles about what that meant. 
He said optimising use of stockpiles and material movement.  What he means (and correct me if I'm wrong) we mine Babel first it's got a shallower, higher grade and flatter (better mining geometry, lower strip ratio) pod at the top.  Then at some point move over to Nebo mine some of that and go back to Bable agin. in the time in between were stripping waste from parts of Nebo and Bable. the pit shells are fully finalised yet and nor what constitutes ore if we include some lower grade stuff. Also as we mine there will be closely spaced drilling which will better define whats ore and whats waste. Actually, some will not be waste but go l to a low-grade stockpile. the nickel price will move around too. the whole thing will be dynamic, computer-assisted re- iterative within a general plan. So you can see there's plenty of room for further optimisation. 
As I said DFS is the first step of that.

Disclaimer: Mining Engineering is the weakest of my mining knowledge areas.