I took it out back 'n' beat 'er with an ugly stick!
ModularGrid Rack
OK, this seems better. All of the voicing is up top, control and modulation is down. I yanked a few things you didn't have already for some improvements:

The Sub Ring. This thing gives you a few more options for mixing, plus it can provide suboctaves and act as a second ring mod source. The suboctaves are the important part, though; if you're doing heavy bass work, nothing punches the crap out of it like an octave-down or two.

VCAs. Yep, there they are. Your problem with them was kind of obvious: no exponential VCAs, plus no actual envelopes. Put those two together, and that's what gives you that 'THWACK' that only a good, snappy attack thru an exponential VCA can get. Why? Well, a linear VCA changes gain based on a linear mathematical relationship with the control signal. But an exponential works on a 'law of squares'-type model, resulting in more abrupt dynamic changes. So a typical sharp envelope attack into a linear VCA is sort of 'sound turns on', but into an exponential it's more like 'sound punches WAY UP'. The Quad VCA has the extra plus of being able to vary its VCAs behaviors between these two, so with a little creativity you can have a whole continuum of 'smooth' to 'OW!'

Power. Try the Row Power 40 instead. Having more current headroom is a good thing, because the farther you can get from maximum load capacity on your p/s, the less thermal wear you'll have. Result: more reliability over time. Never use a supply where your supply capacity is anywhere near the current draw on any rail. ALWAYS leave plenty of headroom for unexpected current issues, such as switch-on inrush loads, etc. The uZeus is great for single skiff builds, but if you've got something more on this size, go big or go home is the rule of the day.

Yes, envelopes. Erica's kickass dual EG/LFO gives you a pair of ADSRs (which you'll want for audio and filter cutoffs, to be sure), plus if needed, these envelope curves can cycle, giving you two more modulation sources in addition to the Maths. And in order to make that fit better, I scrunched the output down to a 4 hp Ladik that also gives you metering on your output level. You'll need to watch your input level to that, as it has no attenuation, but if you need that feature, Ladik has other output modules (as do other makers) that fit the slot that provide an attenuator.

Flow now makes loads more sense. Left to right on audio chain, control/modulation upwards into that. Power next to MIDI, to avoid placement near any audio hardware, in case (not likely, but still...) of any power-line crud that might try and creep into your audio. All input and output is on the bottom, at the ends. Looks more playable as an instrument now. Howzzat?