Yes, I intend to carry it in a backpack - day tripping or overnighting. I also have something similar in my GHB and the family BOB.

I don't think you need a tin to do charred materials. I've only done it a few times in the past couple of years. (Learned about it through ETS, actually. thanks gang!). I've used an Altoids tin, but think you just need an almost airtight (need a way for the gasses to escape, like a hole in the tin top) fire-proof container. les Stoud used a piece of airplane metal in an episode of Survivorman.