like LiFePo4, sodium-ion also won't burn

ie. so the fire department doesn't have to spend three days trying to put out a Tesla fire

for long hauls, not stop and go city traffic, the weight penalty doesn't matter as much once the weight is moving

a tractor-trailer could have a huge cell behind the cab or replacement the massive diesel tanks?

I hadn't considered that aspect. Maybe sodium will see applications for hybrid diesel trains, medium haul trucks.