ESP32RET Comms Protocol

Is the GVRET protocol that’s implemented by default A0 firmware (ESP32RET) documented anywhere besides the gvret_comm.cpp source code? I’d like to develop a RPi application to connect to A0/ESP32RET so that the CAN (J193) data can be processed. It looks like there are two ports (23 & 1000). I’m assuming the ports use different protocols otherwise there wouldn’t be two implemented. Is one protocol easier to implement than the other (ie. ELM?). Let me know if this would better be posted to the ESP32RET GitHub site.