Too many voices and not enough modulation - at least for a setup this size. I would consider taking a look at more envelopes or even a nice function generator, as well as another VCA/attenuator to specifically facilitate modulations of modulation. A module like the Zadar really shines with a VCA or attenuverter alongside it to have more hands-on control of the voltage amounts.
You have a few particularly huge modules in here, and while I think that's actually a good idea ergonomically, it hasn't left you with much room for more modulation with all the voices in there as well. Nevertheless, things like sample and hold or other simple modulation sources will do you a lot of good (and you can get a small sample and hold without much trouble, since they don't really need controls right on the module).
How many voices do you see yourself patching together at one time (drums included)? If it's only 3 or 4, you should be a bit better off, but might still need a couple amenities like what I mentioned above. If you want to run them all at once and really work them, you probably want a fair bit more modulation.
Do you have the standalone case thing for the Ground Control? That extra space could be great for modulation, and it probably makes the sequencer/keyboard more accessible. I understand if you're keen on having it in the rack, but if not, that's valuable real estate.
In terms of voices and sound sources, you definitely want the stuff that speaks to you, but with modulation, it's honestly the stuff that sounds boring, overly technical, or obvious in modular that ends up being the most fun and unique. I would take a look at some Serge and Buchla modules if I were you - not so much to buy them, but just to see how the basic plumbing of modular can help your techno stand out from more rigid and standardized DAW creations (I would also watch some tutorials on Maths, which is not only a great module but a great teaching tool for showing how flexible basic circuits can be). They really illustrate how dense the simple stuff can get and demonstrate how to use one or two voices to make a full and compelling arrangement. Modular techno doesn't have to be minimalist, but it's a lot more fun if it's efficient and all the parts are being pushed.