A little math jargon here. The filters in the EX are time domain filters. The filters in this program are frequency domain filters. What does this mean?
The word "domain" is associated with the mathematical notion of a function. In the synthesizer world this means for one value in the domain (frequency or time) there is one (and only one) value in the "range" (the amplitude).
Though the end effect of both the EX filters and the SSCSSS filters is to modify the relative amplitudes of different frequencies, how they do it is different. The (time domain) EX filters are processing the sound as it happens. The (frequency domain) SSCSSS filters are doing nothing while the sound is happening. The SSCSSS filters are manipulating numbers for the amplitudes of harmonics before the sample is generated using those numbers.