Fair cop vapilot "never say never" point taken !
But the lithium iron phosphate chemistry is inherently very much safer in that the battery materials themselves will not sustain a exothermic reaction
Others especially lithium colbalt oxide (the chemistry used in dreamliner do burn in a self sustaining reaction. A very very diferent scenario
Any concentrated energy source can get hot.. very hot when many kwh are contained in a small space, it is reasonable in an aviation setting that cells should be protected from cascading heat failure. But that is a very much easier (and lighter) ask with lipo than li colbalt oxide