Thanks so much all, very helpful!
@Sweelinck, I'm afraid my knowledge of 16th century French adages departed with Martin Guerre and has yet to return, so I'll trade you an old Yiddishism - "better an honest slap in the face than an insincere kiss." Agreed it's quite hard to ask for feedback once one's gone down the very pricey rabbithole of modular, but I'd rather have honest criticism than false praise. But don't worry, I take your critiques as completely constructive and not at all slap-like!
I'm actually pretty jazzed by this feedback. In retrospect, I eschewed a lot of audio manipulation modules until I was confident that I had an otherwise solidly working instrument and understood how to use a lot of the more "functional" modules (I tried to take @JimHowell1970's tagline seriously). Matrix mixers being a good example - it took quite a while until I actually understood just how flexible and useful one could be in a patch, so now I'm excited for number two (and a stereo one, at that!). Perhaps that A-119 should get a closer look as well, for the same reason.
So it's good to know that my planned rack is in a place where I can explore these sound sculpting modules more comfortably while also saving hp for the future. It's a little overwhelming trying to choose between the vast number of high-quality modules out there while worrying if the amazing demo videos that I rely upon represent a module's actual capabilities or rather the patching talents (and complementary background modules) of the musician filming. Particularly since it seems like a new game changer is coming out every few months. I just finished watching hours on the Spectraphon, for example. To that end, I'll definitely consider the Nautilus, as I see it covers ground I'm otherwise missing and seems fun to play (an issue of key importance to me nowawadays, and one that should have been from the very beginning). The Sinfonion as well, which I had not previously looked too closely at since I didn't realize my rack was large enough to support it, but might be a step in a very interesting direction, particularly with how many voices I plan to have available.
Regarding utilities, I'm a true believer now, so I'm all ears for suggestions. Figuring out mid-patch that I'm lacking the right number of attenuators or inverters or whatevers to accomplish my musical goal is an annoying tradition I'm not looking to continue. Aside from the aforementioned matrix mixers, I'd love to hear what other utilty modules you would consider integral to your systems.
I'm sure I'll be back in 6 months with an updated version of this question, but that's probably how it should be (we're all learning here, afterall). Thanks again!