The problem with the jagged SuperSmoother is a very common error when translating scripts from Tradestation Easylanguage, and many more scripts in this library suffer from this error.
The error is that in tradestation Easylanguage when you have cos(x) the angle x must be in degrees and in PineScript in cos(x) the angle x must be in radians.
To solve the problem you must convert the x degrees to radians multiplying de x degrees by pi / 180.
Thus, the line 13 b1 = 2*a1*cos(1.414*180 / ssPeriod)
should be replaced by b1 = 2*a1*cos((3.14159/180)*(1.414*180 / ssPeriod)) and voilà.