If BYD's testing of their LFP blade battery (as installed in the Seal) is to be believed, the chances of thermal runaway are low compared to conventional LFP batteries and NMC batteries.
"While undergoing nail penetration tests, the blade battery emitted neither smoke nor fire after being penetrated, and its surface temperature reached only 30 to 60°C. Under the same conditions, the NMC battery exceeded 500° C and violently burned, and while a conventional LFP block battery did not openly emit flames or smoke, its surface temperature reached dangerous temperatures of 200 to 400 degrees celsius. This suggests that EVs equipped with the LFP blade battery should be far less susceptible to catching fire, even when severely damaged."