You're right, I don't think you're well enough versed in this...

You're right, I don't think you're well enough versed in this process.

What other Underground mining companies have you actively been invested in or worked for?

Underground mining is very different to Open Pit, what many people in their early careers tend to associate with mining.

Specifically, when underground, you do exactly as you said, target the high grade ore, nothing more, nothing less. You only need to remove waste in order to dig your tunnel to get to the ore, and in some cases digging the tunnel is also following the vein and extracting ore.

Actually this is true in Open Pit mining also, except in Open Pit you need to remove a whole lot of waste material to get down to the good stuff.

In Underground mining it is far more targeted at the ore.

Does it matter how much ore was used? This isn't some Australian dig-and-ship operation. This is targeted underground mining. Their intention isn't to remove the mountain, but to remove the ore contained.

You're right, they could have taken one of the 100+ g/t Gold veins that are down there and uplift it through the crusher and separation process to 900+ g/t Gold. That would just be a moment which is spectacular.

Or they could be running some 0.5 g/t Gold material through which would be more spectacular.

Does it matter how much ore they had to process to get the result? No. Because tomorrow the ore grade will be different as they'll be hitting a different section of the mine. A different vein, a different tunnel.

Bulk ore grading only matters when you have to deal with many more times the waste compared to the ore you are trying to extract. Underground mining avoids a good chunk of that.

Do some homework on the "Resue Mining Method" as mentioned in an NTL announcement from January this year:
https://www.asx.com.au/asxpdf/20190124/pdf/44225sh0bby4c4.pdf