Added some suggestions to your rack.
1U
Quadratt - Tame wild CV from Mimetic and Pam's before sending to BIA and SD
Midi - for clock syncing and melody programming from other devices
Stereo Mixer - to mix and connect to the palette 1/4 jacks
3U
Pam's - Clock and synced modulations
Euclidian Circles - 6 channels of mathematically derived gate rhythms and manual step sequencing
Mimetic - stepped CV sequencing and modulations
BIA - kick or bass lines
Sample Drum - drums and breaks
Versio - awesome FX unit that can be reprogrammed with alternate algorithms
Patch to send modulations like crazy from Pam's and Mimetic. This will bring BIA, Sample Drum and Versio to life
If you'd rather focus on melodies and note programming, then swap out Versio for Scales or Pico SEQ. Maybe drop Pam's since you don't like menu diving, then add one of the note sequencers and keep some effects in the palette.
then... get a bigger case :D