The Project masters spellsilver, and Keltham does think then to run a stricter test.
But by then the Conspiracy has had longer to prepare, with a larger budget once it became clear the whole incredible concept was going to work; and the Conspiracy has recorded far more of Keltham's thoughts, and understood what sort of tests he might run; they spot his resolve the night before it all happens. Keltham's wariness is not roused as it was by the eroLARP tropes, by the supposed Zon-Kuthon godwar, by the strangeness of Snack Service. There are magic items already forged, books already edited.
They pass his test.
And Keltham goes on to reinvent more technologies.