Hmmmm..ok, VCOs. Not quite enough basic ones. You're going to want a few more of the more plain-and-boring variety to either fill out sounds or to use as AF modulation sources for the Graphic and Mangroves. I'd also consider something that can do thru-zero FM, such as a Rubicon or Doepfer's A-110-6. Overall, about 7-8 VCOs, with 3 of those being the 'sexy' variety, should be right. Also don't forget to put a small 4-6 channel mixer close by this arrangement so that you can create mixtures for various purposes, either to feed into your audio chain or to combine VCOs for a certain AF modulation effect. Make sure that, at this point, the mixer is DC-coupled linear, because then you can switch your 'boring' VCOs to LFO mode and combine them that way (or with Batumi outputs[and add its Poti expander!]) as well. You could also utilize the Linix in this way, but having a simple mixer or two (even tho they're BORING) is always something you'll find uses for. Lastly in this vein: ring modulator. Ring modulation is a 'you gotta have it' sort of thing with multiple oscillators, because it offers buttloads of sonic variation for very little price or space. I've been a fan of Intellijel's uMod II for some time, as this also gives you some logical operations, plus allows output of only 'sum' or 'difference' results.
Filtering: moar. Threeler is pretty good, but you'll want a few filters that're different so that you can actually build up several different 'instruments' inside the same modular. Fact is, just because you have all of this stuff in a box doesn't mean that the box can only do one thing at one time. Allow for multiple signal chains...and that requires multiple filters.
Control surface: you're part-way there. Isolate your entire bottom row (which I assume will be at an angle directly in front of you) for things that make other things do things. I would suggest putting your sequencer there, the Ears, the Brains/Pressure Points (and why not add a second Pressure Points while you're at it?), the Planar, and whatever you use for a final mixer. That way, ALL of your global(ish) controls are right in front of you to interact with easily.
Other things: exponential VCAs. The Linix is good, but you want VCAs that are audio-specific toward the end of your signal chain(s) to control audio levels in a way that our ears find conveys apparent loudness. You could consider a performance mixer of some sort, as these can give you multiple audio VCAs AND panning, FX send/return abilities, and stereo output. This, btw, is definitely something that goes on that bottom row so you can 'play' it just like any other control surface.
Multiples. If we're talking 8 VCOs, that gets us toward voltage droop territory, so one for CVs to VCOs needs to be buffered to be sure your tunings remain the same if you run everything off of a single pitch CV. You also want a couple of the boring passive variety to group-send CVs, gate/trigs and modulation signals.
More envelopes. Use something that can do several looping AD or ARs so these can multitask as either LFOs or EGs. MATHS is sort of like this (but so much more!) but I'd consider something like the Quadra or Erogenous Tones's octuple crazy-ass thing. More is always better! Why? OK...if you use an ADSR for your filter, it's even better if you can shape the amplitude envelope differently, as this results in different decay rates of harmonics versus time, which is how harmonic decay works on a physical instrument. So...yeah.
And while I'm on the BORING subject, keep an eye out for where attenuators or attenuverters might come in handy. I like the latter, as you can both scale AND polarize voltage with these. Yeah, they're kinda meh...but they can wind up being far from that when you add them into various control chains for 'nuance'.
That's it for now...it's on a pretty good track, just needs the usual 'rethink until brain explodes' method at this point...