When posting your rack, don't post a JPG pic of it, post a link so people can review your set-up. Just copy the URL when viewing your rack. Like this.
![ModularGrid Rack](https://cdn.modulargrid.net/img/racks/modulargrid_1748118.jpg)
Pam's New Workout has an optional MIDI expander. If you're working with MIDI hardware, that might be very useful for sync'ing.
Steppy is a gate sequencer. It doesn't output pitch information. You have a Beatstep Pro that offers gate AND pitch CV. What do you intend on doing with the Steppy?
You have the Intellijel Quad VCA. You also have a Doepfer Dual VCA. For the build, I think you would be safe getting rid of the Doepfer.
I like the Batumi and Poti expander. But this is a small case. Is there a dual LFO module to your like that's a lot smaller?
For your ring modular, I would go with Befaco's A*B+C. It's a dual ring modulator but has pots included for level control. That will be extra handy.
Speaking of pots... look up "attenuverter" You need a couple of those to change the polarity of your CV and attenuate it. Befaco also makes a great dual attenuverter.
Your choice of filters are a low-pass filter and a low-pass/band-pass filter. That's a lot of real estate for a small case. Unless there's a specific style of sound you're looking to get from your filters, I'd find a smaller multimode filter.
Do you have a noise source here?
Where are the envelope generators?
If you get rid of some of the fluff you don't need, you can also go with a Disting EX rather than a Mk4. You'll get much more use out of the EX.
You can also save space by purchasing smaller clones of the Mutable Instruments stuff. Again, in a small build, you might want to sacrifice a little convenience to get squeeze in more modules (more functionality).