Have you thought about bringing effects pedals into the mix? If you play guitar or have external instruments, Adventure Audio Merge could be one module for consideration, and would also give you input/output for pedals, as well as an envelope follower. Another option to think about to just bring in pedals for audio processing would be Malekko SND/RTN. I find bringing pedals into the signal flow a fun way to expand the palette.

As for filters, perhaps something really aggressive like Flight of Harmony Plague Bearing or Imp? ALM Busy Circuits MUM M8 could also be considered if you would like to have that classic Akai S950 Low Pass Filter.