Hey TOMMI001 ///
Great suggestion! I have a Circuit Tracks and I adore it, I remember throwing a track together within minutes right out of the box and thinking to myself "Man... this thing is AWESOME!" Similar to you, the Circuit Tracks has travelled with me and has certainly earned a place in my heart (and luggage).
My thoughts surrounding the portable modular case idea were encouraged by workflow and inspiration. For me personally, and in my very limited experience with modular (with my 0-Coast, which isn't technically "modular" I guess...), the sound creation is much more organic and rewarding, if that makes any sense. It's more of a process or journey, but when you get that sound (either by accident or on purpose) that you've been looking for or newly discovered, I feel like it's so much more rewarding. To be able to achieve that while on the road with a smaller system would be so cool.
What I could do for now, is throw my 0-Coast in the bag with the Circuit Tracks, and in the interim, begin putting together a larger, more proper eurorack case at home, just one or a few modules at a time as unanimously suggested. That seems like the smarter, more logical path.
I have to admit though, the Palette Case above that has been collectively constructed with the help of Shakespeare and 33PO is pretty fricken sweet!