Keep in mind, though, that the mixer in there does a lot more than just mixing. It has your end-of-path VCAs for signal level control, an autopanner (and manual panner, natch) on each mono input, allows you to use the CUE bus for tuning and other checks on the fly, has your parallel path via the AUX for FX (also with per-channel AUX VCAs), and it's also your headphone preamp.
In fact, this is how you get more into a build in less room for less money. Whenever you have the ability to use something with a large function set as opposed to something basic but which requires a bunch more modules, always go for the multiple functionality devices.
And one last thing: never assume beforehand what you'll be doing in the future with something as open-ended as a modular synth. Sure, it works as a sound design rig just fine...but what if you find out that the modular opens up some new musical directions you'd not entertained before? YT jam vids, live performance, etc...make sure you've got those bases ALL covered, because you really don't have an idea where the synth will lead you!