Great read here, again, Lugia.
I pondered similar questions as I just recently jumped into modular. Even though I did my research, still a few things I’d do different. It just uncurled to me how big the DPO really is. Also, many cool modules are now available as micro-units (clouds, marbles, braids, plaits...). So, gotta swap them at some point. I didn’t go for a particularly small cab, but it’s quickly apparent how critical function density really is. I love XAOC in that regard is awesome with the 10 HP Batumi and Zadar.
And, yeah, mixers. I quickly learned that you’re going to want those for CV and audio separately. So one bottle neck for me is that I rely on a single triple bipolar.
Also, do you plan to integrate your system with other gear? MIDI and/or audio I/O seem to be missing (need for a dedicated audio I/O was something I hadn’t considered).