It’s a very nice little beast with endless possibilities, it appears… 
So far, I have hacked together a few different use cases:
- Roon (volume control in Roon, play controls and playlist loading via RoonCommand)
- HQ Player (volume control, play controls, transport loading and filter/shaper switching via hqp5-control – I did a small writeup here)
- Spotify (volume control, play controls, device switching and playlist loading via Applescript and shell scripts)
A bit nerdy, but it works like a charm. If you don’t fancy the hackery, just wait for the good doctor to release.