What they are talking about here is easily lost in translation.
The spore coat is correlated to how that particular spore was raised or exposed.
The next generation would not have the same coat as it is shed when the spore germinates.
I’ve always wondered if this wasn’t brought into the country in a woman’s makeup case. How many little jars do they keep in those highly guarded little cases? Tin and iron so common for the lids. But I’m not so sure that just exposure to a lid would cause such a signature.
Seems like the media would be the source of the metals.