Ann: Supplementary Announcement, page-6

Your point is well made.

I think they probably didn't have enough of the concentrate available be exhaustively tested. I do think they should have been given a kick up the a___ for not making that clear.

They can assert that the synthetic feed simulates what they wanted to test but I, like you, really only believe it when material from the ore body is used because the impurities and relative concentrations will be unique to the ore body.
I've stuffed around in the lab with things and ended up with a different kettle of fish in practice/ production. There are all kinds of electrochemical forces in play. That's part of why ramp-up of hydromet CCD processes are painstaking.

All IMVHO.