Agreed. Thickness, geology and morphology of this are similar...

Agreed. Thickness, geology and morphology of this are similar (so far) to Oak Dam East which is sub-economic.
It's flat-lying and has an extensive, thick body of massive, barren hematite alteration sitting on top of thin Cu mineralised horizons.

Figure 3 in this paper shows it: Characteristics and Origin of the Oak Dam East Breccia-Hosted, Iron Oxide CuU(Au) Deposit: Olympic Dam Region, Gawler Craton, South Australia

Compare it with the drill section from COD's announcement. See the similarities?

Then compare to the economic systems at Olympic Dam, Carrapateena (and possibly Oak Dam West) which have much greater vertical extent. That's why large-scale caving operations are potentially doable.