...that Foma has quietly and secretly changed the emulsion...
Just a side note on that.
We (the manufacturers) constantly have to change things ‘quietly and secretly’.
But rest assured, we don’t do it on purpose :-)
Because whether it’s done ‘loudly and openly’ or ‘quietly and secretly’, any ‘tinkering’ with a silver halide system is highly risky, expensive and makes absolutely no commercial sense.
In that respect, I am quite certain that the folks at Fomate, if they really did tinker with something, had no choice but to do so.
But that’s really just a side note and not an answer to your actual question (to which I can’t contribute at the moment due to a temporary absence from Lith).
Best regards,
Mirko