A1502 MacBook Keyboard Not Working

I feel I have exhausted every option to fix an A1502 MacBook keyboard but I wanted to ask here in case I am missing something obvious/stupid.

In a nutshell; none of the keys work except the power button at any point (not even outside the OS or after multiple fresh reinstalls of Catalina or Mojave). The trackpad, backlight and any external keyboard (wireless or otherwise) work perfectly at all times. A replacement internal keyboard also does not work, Safe Boot does not work, SMC, PRAM or any of that stuff does not work nor does a hardware test in or out of the OS detect any issues.

Any ideas? I hope you enjoy a challenge!