I've been using lipos for the best part of 10 years now, not once have I had them explode on me or over charge, the only Lipo I had puff on me was when my fast electric boat flipped on me & water got in
I've never used a Lipo bag or ammo box, that came mainly from when smart chargers weren't around so people jumped on the band wagon
If treated correctly then danger is kept way below minimum
Just keep an eye on them while there charging, any hint of puffing or heat then take it off & leave for 24 hours