On macOS you can set up some kind of labeling for audio inputs and outputs.
Here are the steps:
- create an Aggregate Device in the Audio-MIDI setup app,
- select your aggregated device and provide labels in the area [2] in the screenshot,
- select the created aggregate device in the Gig Performer audio options. Note that Gig Performer shows these labels that you have previously configured.
- if you hover over I/O pins in the Wiring view, the corresponding tooltip will appear, showing the label.
(source)