My personal advice as far as LiPo failures would be as follows Dave
If charging in a LiPo bag make sure that you are easily (and safely) able to disconnect the LiPo (in bag) from the charger with some form of Deans plug release system.
If its safe to do so chuck the bag onto something that wont burn and cover with a bucket of sand.
If charging out of a bag, throw a bucket of sand onto it.
The only way (as far as I know, but im happy to be educated) to "put out" a LiPo fire is to cover it in sand.
If I didnt charge in a bag and my S2/B44 went up with LiPos in it id have no choice but the cover it in sand, probably on my table
Messy.