In an ICE car fuel and ignition sources are generally separate there's little to be gained by being unsafe with fuel. In an EV your fuel and ignition sources a

In an ICE car fuel and ignition sources are generally separate there's little to be gained by being unsafe with fuel. In an EV your fuel and ignition sources are fundamentally inseparable and you can gain a lot (range/capacity, charge time/peak power) by being unsafe with it (running the battery to the ragged edge of what it can tolerate). The fact that in response they quickly rolled out an update that neutered a large amount of capacity is far more interesting than the fires themselves and probably what the NHTSA wants to look into.