For anyone looking, the keymap is available here under "Sword Keyboard" to make VIA work: https://wiki.keebmonkey.com/en/guides/doiofirmware
Import it under design. Anything to do with changing the backlight doesn't seem to work for me, but I can reassign buttons.
For newer versions of VIA you need to edit the file and change "0xFEED" to just "FEED" and "0x6060" to "6060"