However, if it's similar to how Apple does it, the chip might be bound to the processor via a serial number or some other magic that's burned into the NAND at m

However, if it's similar to how Apple does it, the chip might be bound to the processor via a serial number or some other magic that's burned into the NAND at manufacturing, or OTP on the processor, or something else. It's not just a matter of "oh just go get a Hynix NAND part from DigiKey and reball the PCB". At minimum you need to copy the data over. At worst you need to bless the part with whatever secret sauce Tesla is using at the factory.