You ask if there is fundamentally something wrong, something that the experts missed. The metallurgy issues explain why it is low. And it appears that most of the experts haven't missed them.

The day ZEN announces that they have arrived at a baseline flow sheet that they are happy with, and are therefore moving on to bulk scale testing and starting the PFS, is the day that some "true value" will be realized. Anyone who believes a company will put up money for a product that hasn't been proven to be economically recoverable is investing with their heart, not their head.