"I pointed out that the primary porphyry deposit was indicated as being at about 5000 feet deep- my main point being that we might not see the highest grades of ore until we reached those depths."

Respectfully, my friend, I keep countering your observation by saying I believe you are under a misperception, that skan/CRD is likely to be on top of the porphyry, not at the depth of the porphyry.

Here is an illustration demonstrating that, but without evidence of folding (for those who may look for that).

Note the red and near-red zones.  Also, note that this is an illustration of a discovery by another company.  It is not meant to be an example of all types of porphyry deposits having accompanying skarns/CRDs.  In fact, I think such deposits can exist without being related to porphyries - I am following a few such explorations elsewhere. 

https://finance.yahoo.com/news/core-assets-taps-crd-discovery-130000152.html

I have no interest in Core Assets and do not have them on my watch list.  FWIW, our target is likely to yield a far richer mix of metals and from a larger overall footprint.  So this explains their "discovery" cap rate of nearly 15 million compared to LBSRs at about 38 WITHOUT discovery.