Unfortunately, my Jeep isn't parked near my workbench so using it to test my decode logic (and eventual display) wasn't going to be feasible. And sitting in the driver's seat isn't the most comfortable of development environments.

Instead, I opted for using a PyCom ESP32 running micropython to create an ECU simulator. And used NickInTimeDesign's Renix Engine Monitor II+ as the reference implementation to verify the accuracy of the simulator.

And, to simplify development even further, I was able to use the same Python ECU simulator on my Mac to send a byte-stream to a socat created virtual serial port so that it could be used to develop and test the RenixMonitor decoder application without even having to keep a breadboard with jumper wires nearby.