Here's something I know you all would like to hear.
I created and tested an image than can be DIRECTLY flashed from the stock firmware without the need for tearing down the unit and messing with bootloader and UART.

This port is now good to go.
But, there's still a BIG catch, the LTE module still needs some love. I will leave adding support to LTE module to the capable hands of others like the Backspace team.
You can't use this device as a modem if you decide to flash OpenWrt atm. It will only function as a router. Also the telephone port still needs enabling support to function.