Minimal wiring is done now, enough to get everything powered up and r2_control installed.
A quick flash of an SD card, some tweaks to the install instructions, a few small tweaks to the code to make first boot a little smoother, and shes alive!
Only got audio working for now, but it meant I could test the base code and web interface. I need to get a remote working next I think, and then I can start working on interfacing with the Odrive and Q85 motors. Theres already a python module for that, so that saves a lot of work. Unlike the Sabertooth, which required me to write a python module to interface using serial.
Also, the documentation is now up to date for the latest version of Raspbian, and the code now auto creates basic configs correctly so it will work on first start without having to pre write any configuration files. It should also be easy enough to write a setup script to install required packages and python modules.
And of course, seeing as the Pi is powered up I can now remotely access it to do coding from the comfort of my office.