Your answer of "40Mt at 0.9%Cu" (apparently based on SFR's Dec...

I think that even long term investors in a company, whose share price has risen strongly on the back of a discovery, would be wise to calculate and keep an eye on the average grade reported as drilling progresses. It will be much easier and more reliable to do that once CBE start reporting proper assay grade figures, instead of having to rely on visual estimates from graphical pXRF data, with the associated uncertainty around pXRF grades vs proper assay grades..

Your answer of "40Mt at 0.9%Cu" (apparently based on SFR's Dec 2020 Reserve estimate for the T3 deposit) needs to be qualified.

It is apparent that the Grammer discovery is a relatively narrow, steeply dipping, tabular deposit on the limb of an anticline, hopefully extending to 500 - 1000m depth. The configuration is not suitable for open pit mining - so far, it appears suitable for mechanised underground mining.

Therefore comparison with the Zone 5 UG mine makes a lot more sense than comparing it with SFR's T3 planned mine. T3 is near surface, relatively flat and shallow dipping (about 30 deg average) and wider in plan view than Zone 5. T3's configuration suits open cut mining.

The diagram you posted on 10.9.22 (https://hotcopper.com.au/posts/63623822/single) contrasts the configuration of a Zone 5 type deposit with a T3 type quite well.

Another point to bear in mind is that the Resource grade reported for Zone 5 has a 1.0% Cu cut-off grade, whereas T3 has a 0.3% cut-off grade. It is what you would expect to see when comparing a Resource grade for an UG mine with same for an OP mine - the OP mine extracts larger volume/lower grade optimising recovered metal.

It would be more realistic at this stage to aim for an average grade of about 2% Cu, close to the Resource average at Zone 5.