Ann: Further high-grade results, up to 3.36% Li2O at Mavis Lake, page-52

I guess it boils down to the extent of the resource as that drives economics. Grade is also a key. Early days here but suggest some might want to have a look at LTR which will be developed as an underground operation. It can do that because of size of resource and grade. Grade here is good, so it becomes one of ensuring have enough resource etc etc.

Yes open cut is cheaper, but has more waste. But the cost of underground mining depends on the compactness, grade and quality of the resource and actual underground mining technique used (as there are differing approaches). Need the drills to increasing the resource size.

You also see mining projects commence as open cut and then transcend into underground mining. Anyway, a bit early here to discuss mining techniques IMO, and potential development scenarios, until determine the resource size and grade etc etc on which then feasibility studies are done.

Hope this helps.

All IMO