IMO...We would only get 100% of NPV if we were basically operating 

Well that is not the premise of an NPV.  NPV is the fair value, today, given everything including the cost and time to production and time to revenues.  A project's updated NPV at production is way higher. 

Because of natural uncertainty about the future the NPV is derived from very conservative estimations, no rise in metal prices for a generation is assumed yet all capex/opex costs are inflation indexed, and the NPV for a copper mine uses very punitive discounting rates.   8% discounting of all revenues is ludicrous for a polymetalic mine of increasingly scarce and increasingly critical commodities.    

We're in a different world now, imo.  I think getting 100% of NPV should be achievable in this historic energy transition period, and especially during periods of spurting prices like we have now...

Teck's jr-starvation strategy is currently exploding in their face, and I'll bet Newmont is really pissed too.