Xiaomi Mi Router 4A Gigabit Edition (R4AG/R4A Gigabit) -- fully supported and flashable with OpenWRTInvasion

that was scare got to u-boot and did setenv uart, telenet,SSH and then reboot and it kernal paniced everytime

In the end I used option 1 and uploaded image from TFTP.

This is certainly not for the faint of heart