Long time, no update (again); while I was hoping to perform the conversion on my 'actual' 530i over the New Years holiday period, life got in the way.
The wiring is coming along slowly, with JBE, CAS, DME and EKPM modules up and running.
I did get some time to further develop the CAN translator firmware and put together a small UI for diagnostics / configuring the translator:
The CAN translator is of my own design and is based on a PIC32MK with four CAN channels, three switch-to-ground outputs, three switch-to-VBat outputs and three optocoupler inputs.
The firmware uses FreeRTOS for low-level task scheduling, TinyUSB (diagnostic interface per screenshot above, implemented using WinUSB, not CDC), and custom libraries for managing all of the peripherals. The firmware is field-upgradable with only a laptop and USB cable too