The only real gauge of HMC production is the quarterly reports....

The only real gauge of HMC production is the quarterly reports. Next one not due until probably mid to late July.

Q1:
3,359,399 tonnes mined
Average grade 1.02%
29,855 tonnes HMC produced

That pretty much says yield is about what you would expect from DFS numbers but mined tonnes are way down on nameplate.

It's entirely possible that in two months since with two shipments of 10-11kt each that they mined at a higher rate and produced more HMC that was not sold but the narrative of the 6th shipment announcement does not suggest that. Based on previous announcements I would expect that if they made 15kt or 20kt that they would make that public as it would give the share price a boost.

Also why would you stockpile HMC for an MSP that is in commissioning? That does not make sense. Surely you would put the HMC through the MSP and make final products to sell and if the final products don't meet specifications yet then just combine what you do make and sell as HMC.