Why would you?
Put clean emmc in the device and simply ask the firmware via ufi toolbox and the unit will operate.
if emmc is clean it defaults to start with userarea.
If you use used emmc, it is important that the rpmb block is clean...for example, a popular KMVTU000LM-B503 goes,
just do the upgrade before installing it.
And all will turn out, good luck.