PEA Sensitivity Analysis - Medium Scenario

I have been scanning the full PEA report and came across some medium sensitivity analysis on pages 266 to 269. If I am reading and interpreting this correctly, its not going to take much to double the project NPV. I am only focusing on the production variable and specifically the 125% variable which implies annual prodcution of 25K a year. Other variables being equal, this results in an NPV before taxes of US$2.033 billion and an NPV after taxes of US$1.449 billion; an IRR before taxes of 33.3% and after taxes of 28.7%. The numbers for 25k production a year are mind-blowing. I must be doing something wrong. If someone can correct me please do. If my observations are correct then this is a BIG SELLING POINT.