Hello,
Have you think about getting a module like Morphagen or Nebulae 2 ?
It could be a great addition as you dont have any "real time sampler" like module to twiste up your patch...

Regarding VCA's, you could consider replacing the MIDI extention with a ADE-50 3x Lin VCA to save some space and be able to manage advanced CV modulation.

Best regards,
Pascal.