The caldera cone comes in two varieties, aluminum or titanium. The aluminum one is pretty easy to mash, so the plastic container is almost necessary. A few users have tried a smaller diameter plastic container. The titanium variety is a lot harder to mash. Some users roll it up and carry it in a fabric bag or cuben fiber bag. It is still possible to mash it, depending on where this goes in your backpack.
I think it would be better if the plastic container did not have the screw threads. It would be less secure, but it would be better for eating and cleaning.