This is interesting! My approach might be heavy handed but…
I ended up going this route to get diagnostic data into HA:
And my plan soon is to ditch the head unit altogether and fashion a double din base vesa 100x100 mount for an iPad case, try to tidy it all, run power, ethernet, a DAC for stereo, all to the iPad. And I’ll have splitscreen HA and navigation, being able to control Spotify on the iPad as a music output device.