Just though I would let people know that it is possible to remove the MX25L6406E flash IC onboard and write the original firmware to it using a CH341A programmer. I've successfully done this with a bricked router. If anyone wants more details, let me know.
Here is a link the the original firmware binary to load onto the IC: https://mega.nz/file/rypR3QwD#lJDHASHKZsIv43PZp3RZhTaE_bZ8j_U4KWemrZpu1b0