Came across the figure8 knot, also from Aaron Trautwein, who also has a book, so I added it into the trefoil script.
It looks like a lot of numbers were adjusted slightly to two decimal places, to get a "pleasing" curve.

There is one too many points in the point version, so the index still needs to be modified slightly.
I guess the curve factory version is OK with respect to the "extra" point.
Also the pointfactory should not be created outside the loop, in some prior point scripts...

- Brian