As, always, PE, thanks for your ongoing contributions...  From
an academic standpoint, a more effective preservative is
interesting. But given reasonable care in drying and storing
hand-made tissues, they do not seem to be particularly
susceptible to picking up nasties, and the broader experience
base seems to suggest that Thymol is sufficient. In all my
reading of various carbon threads and fora, I don't recall
seeing any mention of Thymol-preserved tissues deteriorating due
to microbial or fungal action.  Speaking from my opinion, here,
if that advanced preservative is useful or necessary to your
emulsion work, that should be the primary focus (and "market").
If it is readily obtainable, then some may choose to use it for
their carbon tissues or other purposes, but I doubt it would be
the driving force in continuing development of it. I hope that
doesn't come across as too discouraging, but that's the way I
see it.