I made the above build make more sense. Vide:
I tossed the majority of the adders and buffered mults as being superfluous. However, note the arrangement at the top left...in this case, the adder and buffered mults are PAIRED here so that you can use two separate CV channels (you'll see why in a bit) and have transposition control over each separately.
Now...why two channels? Here's why...I split out the "voice" into two discrete voice "zones". On the left end, you've got your stereo VCOs grouped together, then this feeds to a Hyrlo, set up for three stereo inputs to one stereo out. Then there's a Morgasmatron next to this (I tossed a lot of the excess filters, also...this and the other two are placed to be used by the separate "voices") for the stereo filtering. This would then output stereo to a pair of strips on the Performance Mixer. Then, right after that, are the monophonic VCOs, and a dual VCA/mixer (1/2 of a Veils, actually) is right by those for summing. OR you can use the inputs on the Fold Processor for summing, OR you can send the individual VCA outs to the Fold Processor and have IT serve as the VCO summer...plus the source for sub-octave bass! After that, I kept the Tiptop Steiner-Parker clone for even more post-sum processing then the A-106-1 is intended as a final VCF pair for THAT voice. You'd send that from there down to...again...the Performance Mixer. By doing this, you now have a split between a "pad" voice and a "lead/bass" voice, with the outputs of both going right to the level VCAs in the Performance Mixer.
Your drums are now on the next row down, next to the Konstant Labs PWRchecker which lets you keep an eye on your DC rail performance. The thing next to the BlckNoir isn't a mult...it's actually a fixed-pan stereo mixer (the white-ringed points are the L and R outs) that lets you sum that module down to stereo. After that, the SampleDrum...then a 2xSAM handles the stereo summing of all of that. Its output would go to...yep...two more strips on the Performance Mixer. All of the modulation sources are next...I added the expanders to the Batumi, Zadar, and Quadrax for even more flexibility and interaction between the mod sources, plus a Tenderfoot 3-in attenuverting mixer in the middle for polarization and modulation summing. Each attenuverter can be broken out of that, also.
Bottom row got beefed up quite a bit. Everything from the Pam's to the quantizer are co-located so that you can screw with timing more easily. Plus, there's another adder next to the quantizer so that you can add its output with another CV...and of course, that meant putting the OAx2 by it for a good DC offset source + an extra attenuator. The MISO logically fits next to this, and allows you to manipulate your mod signals globally. But where there should be VCAs...well, there is, but by using the VC8, you get much better functionality AND save about $80 over a pair of the Tangles. These are your linear VCAs for CV/mod manipulation...as the final audio VCAs are actually in...here it is again...the Performance Mixer. Your effects are next...and again, the goal here was to up the capability AND fit the space, so I went with a MSCL stereo compressor for mashing the stereo drum feed (makes it bang HARDER), a Statis Leak (reverb, tap delay, chorus in mono-to-stereo) and the Echoz. After that...yep, there it is...the PERFORMANCE MIXER. This has your final audio VCAs, plus it has a mono FX send and stereo return and a bunch of other tricks that makes this WAY easier to use. Then I followed that with a FX Aid XL which you can either feed the stereo mix through and control the wet-dry mix...OR you can use the second stereo input on the Happy Nerding OUT as a second stereo return, which is pretty convenient! This also has your headphone preamp, main output metering, and transformer isolation which you can oversaturate a bit for some extra warmth.
I got rid of ALL of the small 2 and 3 hp mixers, all but two of the adders, all but one of the buffered mults (which is now where it needs to be...the rest made no sense, and instead of those expensive things, just use passive in-line mult widgets), and a bunch of other things that just didn't fit together nicely with each other. And that last point is key here: the subsystems in here are now PROPERLY grouped and outfitted with their various support modules for ease of use and better internal routings. And I put it in a wood cab like the Pitt 420 so you can get a better idea of the final looks. Result: much tighter configuration, better ergonomics overall, plus much more "readable" where the subsystem patching is concerned instead of having subsystem modules scattered all over the place. And the addition of that WMD Performance Mixer is not only designed to streamline workflow, it ALSO has enough remaining inputs to mix in any "wing" cabs you might get in the future, or you can also send the SV-1s to those since their outputs will be at the proper level, letting you directly integrate those into the final mix. Also, if you go to an arrangement of wing cabs, you can shuffle things on the bottom row so that the Performance Mixer can be expanded with two more input strips, direct mutes, and CV over AUX sends on your first four strips. No room for that YET...but it's something to consider if you go to a "next stage" build.
The power draw here IS HIGH...but by putting this in a EP-420, there's loads of Amps to go around. Oh, yeah...the uZeus went away, too, since the EP-420 has those STONKIN' DC supplies already in place!
EDIT: oh...and I saved you about $300 here, even with expensive additions like the...gotta say it one more time...PERFORMANCE MIXER! haw!