I agree, it was just the comment and reaction to my post that I found strange. I wouldn't charge them in a box but I will keep them as safe from damage as I can by putting them in one.
The BMFA has a battery safety booklet that is an interesting read - I'm not sure if it recommends storing your lipos in a combustible foam and cardboard box!
In the model car world, it used to be, and probably still is, a requirement for batteries to be in safety bags/containers by the BRCA, or the insurance became an issue.