Another idea for that last 6hp -

ES Disting mk4 (VCA/env functions as before but much much more versatility if I want to do something different)

plus another 2hp module - more vcas? or 2hp verb (replaces need for ext fx when going portable but the SV-1 output module is mono so stereo output probably useless?) or something to add to the 2nd vco sequencing options (2hp Brst or Euclid or some logic?)

A better option? (I'm almost 100% sure the Disting mk4 would be useful in my later, bigger rack so not a wasted purchase)

https://cdn.modulargrid.net/img/racks/modulargrid_968599.jpg