I have tried, but I haven't found it. If anyone still remembers where those discussions are, please link them here.It's been discussed in this thread and a few others, Rudy Vey pointed out the Pur-tech is a completely different fiber than the STF fiber...
Otoh, I found some contradictory information about the EJ STF knot, someone (@nav ) said that it isn't the same fibre as the Muhle STF anymore.
Synthetic knots are just