Of course, it would be bad if you could use the by-far-most-HP-ingame-object as as flexible wall-augmentation, so I understand as it is now, you can carry it when not empty.
But that alone voids all the purpose and cost of it.
The leanto gives a good idea about how to solve it.
Idea:
- make metal chest immovable when not-empty, again
- make it so that you can walk through the metal chest, like it is for a leanto
If that is doable without too much effort, and without unintentionally enabling to stack metal chest into each other like logs, then this would be a good solution.