maybe straying from the topic a little...maybe not. I don't mind the weight of the canister so much, but I do think they could design the shape a little better.
Instead of the pure cylindrical design, if one side was slightly concave it would conform to the shape of the back a little better.
I should point out that I don't stand my bear vault up in my pack, rather it is in the lowest part of my pack laying down.
The shape would probably not have as much strength as a proper cylinder, but it would certainly relieve pressure points.
I may experiement with heating my bear vault and reshaping it a little bit.