Always educational to see Lugia’s Suggestions.
Two additional thoughts:
Going for an Intellijel 7U case with the MIDI module, Audio I/O and two Quadratt attenuverters will give you more space that isn’t going into I/O and power modules.
The Quad VCA comes in a neat micro version, saving you another couple of HP, as does Plaits (and marbles & Clouds).
That way you could fit in some performance modules, such as a Voltage Block or bring back Pam’s. Or, for extra ambient duty, add Plancks, which is a micro-Forms module.
Don’t forget about Poti to go with Batumi, which gives access to the jumpers on the back in a more user friendly manner.
Here is what that could look like:
