Thanks very much for all the advice! and sorry for the slow reply.

So, I have gone through many changes of approaches and iterations just in the last week.
I’ve made the case smaller - mainly just help me reduce the amount of modules, I think this size is better - looking at my “local” store, I’m leaning towards the Erica Synths 2x104HP Aluminium Travel Case With Lid
Not that I need it for gigging but seems to be good for price, power and availability (Can’t see th Mantis cases available anywhere in Australia yet)

I got rid of the idea of sample/beat slicing in the case, along with drums - like you said - also most of the osc/filters I have can be pingable for synth perc.

I may be a bit confused with the difference between VCAs and attenuverters, if both have CV inputs, aren’t they the same - only attenutervers are bipolar?
Yes, you’re right the motu does have DC-Coupled outs, perhaps I could get away with ditching the ES-3. However, I’m also thinking about send audio through these outputs, would I need dedicated modules to boost the motu outputs to modular level? If so, it may end up costing the same as the ES-3.

To be honest, I wasn’t thinking about CV at all but moreso processing audio from Ableton through the case. And processing outboard gear via Motu to the case…
Maybe I should instead add another 2xSAM - these can apparently be configured to be a line-modular boost via jumpers on the back.

I looked at clouds and kammerl beat repeat, however it is still not really what I want, but anyway - I decided to do this in Ableton.

ModularGrid Rack

So, this is my updated case, not sure if you can see the modules to the side, but my most recent omissions are the 100 Grit, swapped for the Steady State Gate, removed Worng Acronym (I really wanted this but can’t justify the price for an OSC), and took out the FX Aid, in the hope that Monsoon (Clouds) can cover reverb duties, and any time based FX not covered by Clouds, Prism or Crush Delay I could hopefully get out of Disting EX.

However - I think something/s else needs to go.

Wondering people’s opinions of what is more valuable out of Pachinko (Marbles) and Pam’s Pro workout, and also if you think I need the 0chd?
Seems like I have a lot of LFO modulation?
I’m leaning towards keeping Pam - but only because marbles was a late addition. But they’re hard to compare since Pam seems like an arranger and Marbles is more performable.
Or should I get rid of all three?! :)
Considering that - I have outside gear that can seq trigs/CV, albeit limited with minimal Euclid/random functions - such as: Keystep Pro, MicroFreak, DFAM, Neutron via midi input and a soon to be modded Roland MC202 with new Tubbutec seq, even the Roland TR8S can switch it’s individual outs to trigs.

Also, what specific utilities you would add to this?

I guess I need a mult, mutes/a-b switch? Anything else? Maybe a S&H?

Also - I’ve got the 3xMIA there to double as extra VCAs/mixer - can these also be used to reduce voltage down to line level? - for example plugging into an external sampler/looper
EDIT - OK, as I was typing that I realised the answer is likely no.
So - yes, like the 2xSAM for line input - I think I want at least one stereo line out in addition to the ES-6 interface to the motu/computer.