Fiddling around with a convoluted method of setting up macro keys on Mac OS. I'm using the old faithful Pimoroni RGB Keypad with a Pico, some basic CircuitPython keyboard stuff, and these two nifty apps:
switchaudio-osx: CLI utility to switch audio source
https://github.com/deweller/switchaudio-osx
icanhazshortcut: shortcut manager to bind any keyboard combo to any command
https://github.com/deseven/icanhazshortcut
Anyway it's working nicely for me right now! So far I've got headphone/speaker output toggles and volume control sorted. Just 12 more keys to assign 🤔