Hello WoollyBird, I don’t know about Patchbox OS, but you can basically use this work around that will just send the init command to the codec at boot to work as a basic I2S dac:
-set an I2S device, if needed you can use the basic installation script of the mic+
-then follow the instructions to run the scrit at startup: https://github.com/RASPIAUDIO/UltraAndVolumio
let me know