From what I can see the original geologist's assessment was that...

From what I can see the original geologist's assessment was that higher grades were contained in vertical "skarn" style intrusions and the multiple small pits and the original PFS was based around that scenario with multiple targeted higher grade pits combined with a fast track construction method to get the project cash positive as quickly as possible while continuing to drill while producing to pay for it.
In simple terms , the new guys are saying , no it is not vertical intrusions but rather a horizontal "halo" style deposit which lies more horizontally so the need to have a small number of larger pits . Obviously the feed grade also affects the plant design.

In PFS - Mk.2 this has resulted in lower grades overall , bigger pit shells , increased the tonnage to be milled by 33% , reduced the plant feed grade by 25% , and increased the Life of Mine by 22% to achieve the same gold output approx. as originally .

So in PFS - Mk.1 every consultant who followed on took the original geo's thinking and analysis as being correct .

The latest geo's appear to be saying that the original geo's thinking was not correct and this has effectively changed everything (although I do not think this was a reason given at the time.)

Is this how others read what has happened based on what has transpired since or am I way off the mark ?

Based on PFS-Mk.2 we now appear to have a completely different project with percentage variations well outside what would be considered industry norms.

My opinion only and will appreciate some feedback to assist make some sense of the unfolding story and try to see through the smoke haze and mirrors on this mystery tour .