I just have individual 3U cases I wouldn't recommend it for everyone, but I play a lot with other people and keeping my case setup small helps me stay creative and engaged while not hogging up too much space for others to play in.
One is a "dedicated sequencing rack" for my Nerdseq and one is just Buchla Tiptop modules supported with a couple utilites in a Niftycase (this normally sits with my non-modular gear). I also have semi-modulars added to this and a Microfreak nearby to play CV and Gate into synths as well (and just because it's awesome for layering on top). I want to get one more 104 (or even 126) hp rack for random stuff I want to try (though this has sort of accidentally laid itself out as a monosynth that I could also take out and use separately). This all sounds chaotic, but it's actually working quite well for me, and once it's set up all together it's not much different from just having a Mantis on the table. When I go out I just unplug the piece I need. It seems scatterbrained from the outside, but if I had everything in one case, it would be harder for me to scale up or down as needed. Also, I don't really want to expand much further than that - it's already quite a bit for two hands, especially when one of my semi-modular units is a big Finegear Dust Collector that I would keep before any of it. I feel like anything else I do would just be starting an entirely different setup, and two is plenty. I still have a Polyend Tracker/TX81Z based setup and a DAW as well, and I can't do everything.
I wouldn't necessarily present to people what I've done as advice, but I would present it as an example of trusting yourself to know what you need and what produces good habits for you.