Not sure where you get your royalty rates - perhaps the 2.5pct...

Not sure where you get your royalty rates - perhaps the 2.5pct nsr royalty to be paid to Raging Bull (good deal for them) who sold the project to NCZ? The owners of Raging Bull (who happen to be on the board) will be paid whether the mine is profitable or not.

Now QLD royalties are closer to 5pct for zinc and silver.
https://publications.qld.gov.au/dataset/quarterly-and-annual-metal-prices-and-variable-rates/resource/3003cc5d-8edf-4ef3-b4b6-8ba2cfdc9.1bd

for whatever its worth - Pattos last report had royalties of a similar range to mine.