I agree, watching the videos i was thinking of encore by Tangerine Dream, on the first track some of the sounds made, seem to come from a Fixed Filter Bank and a phaser i guess?
One of the things that really appealed about the synth but have not really explored too much until your post.
I guess the idea was to have a bank of 12 band pass / reject filters with adjustable resonance but it doesn't seem to work like that and not like the ones in the videos you listed.
I had a good play round with the bank earlier and when you turn the a knob to 0 it kicks out everything rather than just the particular frequency band say 2000 etc.