"That 4Mt of mineralisation, even at 3%, is only 123kt of...

"That 4Mt of mineralisation, even at 3%, is only 123kt of copper? That BHP isn't interested in assets that don't produce >>200kt Cu per annum for >25 years? That for Danvers to get big it would need to grow to 166Mt? A comfortable 4000% more than it has here?"

How can you assume we need 4000% increase in tonnage to be economic ?
I may as well say if you are going to throw numbers around I Intuitively feel for a starting point about a 1000% increase in tonnage at 3% grade would be economic on a capital intensity per tonne thematic ie finding another 10 Danvers in the area but not necessarily on WCN leases that would warrant the expenditure on infrastructure in a remote inhospitable location .

So A 3 Mtpa plant processing 3 % copper at say 80Ktpa of Cu in concentrate with Ag credits would bring in about US $640M in net smelter return sales (about the same as a 190k oz per annum gold miner at current spot ) maybe not big enough for BHP to buy out but intuitively large enough for a mid tier company or private equity (ie John Hancock and relations ) to buy out.

Lets say a OC cut off grade of 1.5 % Cu ( guessing a 10:1 strip to 120 meters similar to Oz but costs twice as high so cut off grade commensurately doubled from .75% Cut off ) and they are running 3% Cu that is fair bit of margin on $640M

Yes none of the numbers are qualified ( especially because we only have a few drill holes in 150 meters of strike ) but neither is your assumption of needing a 4000 % increase in potential resource without references .