Livengood Gold PFS

https://www.juniorminingnetwork.com/junior-miner-news/press-releases/393-tsx/ith/109851-international-tower-hill-mines-announces-pre-feasibility-study-results-on-13-6-million-ounce-gold-resource.html

International Tower Hill Mines Ltd. ("ITH" or the "Company") (TSX: ITH) (NYSE-MKT: THM) today announced the results of the Pre-Feasibility Study (the "PFS") for its Livengood Gold Project (the "Project") located near Fairbanks, Alaska. The PFS details a project that would process 65,000 tons per day and produce 6.4 million ounces of gold over 21 years from a gold resource estimated at 13.6 million ounces at 0.60 g/tonne. The PFS utilized a third-party review by Whittle Consulting and BBA Inc. to integrate new interpretations based on an expanded geological database, improved geological modelling, new resource estimation methodology, an optimized mine plan and production schedule, additional detailed metallurgical work at various gold grades and grind sizes, changes in the target grind for the mill, new engineering estimates, and updated cost inputs, all of which significantly de-risk the Project. The PFS has estimated the capital costs of the Project ("CAPEX") at US$1.93 billion, the total cost per ton milled ("OPEX") at US$13.12, the all-in sustaining costs ("AISC") at US$1,171 per ounce, and an after-tax NPV(5%) of US$400 million at $1,800/oz, US$975 million at US$2,000/oz, and US$2.3 billion at $US2,500/oz.



At $1,680 POG base case, it has NPV 5% of $45M and an IRR of just 5% for almost $2 Billion CAPEX. If you read the technical report below you can see similarities (but by no means identical) in the deposit to Korbel. Mainly being a low grade deposit mostly hosted in quartz sulphide veinlets. I assume heap leach is not possible due to sulphide content of ore similar to Korbel which leaves conventional methods which don't work at these grades.
https://www.ithmines.com/_resources/technical-reports/ITH_Livengood_43-101_Technical_Report_06Sept_2013.pdf

My question to HC is, what differences do you see between the proposed low grade milling operation at Korbel and Livengood? I know ore sorting is proposed as the key to unlocking this deposit by NVA but there is no currently operating gold only mine using ore sorting on this sort of scale that I can find globally (happy to be proven wrong here). If ore sorting was the answer why are they not going to use it at Livengood? Livengood need a 50 mile powerline but have a paved road, Korbel is more remote so what does that mean for CAPEX? If Korbel scoping study yielded similar results to Livengood surely this is why it was not released to market as promised in 1H 2021.