So which concept are you preferring?
I can see that its nice to have some portable gear, I don't consider my main case Portable cos its Blooming heavy but I'm working towards having a my Top Case and Percussion Case as being portable and easy to combine with a Beatstep Pro. This leaves my Main Case to be more Generative and experimental.
I want to develop another case that will be more about weird shit and sound mangling from external sources like Pizo pickups etc.

They're all great! I built up these meta-modules not so much for portability, but ergonomics. Each pod has a focused set of fuctions. I wanted the ability to easily rearange groups of modules on my desk depending of the session and to create building blocks of function to help me stay focused and organized while playing.
As for concepts I gravitate towards sampling of all kinds from macro to micro using these modules and auv3 apps/vcv rack via the es-9. Tempi has been especially fun, but they've all got their charms.