The Inspector always shows the selected cue, so one approach would be to make sure that the selected cue is always the last audio cue that was played.
Here's a way of doing this
1. Unlock the playhead and selection in settings/general
2. Hijack the Spacebar GO by deselecting it in settings/Keymap
3. In a separate cue list make a timeline group containing a START cue targeting the Main Cue List and assign SPACE as the hotkey trigger for this cue in the triggers tab.
4. In this Timeline group, make a script cue with this script
tell application id "com.figure53.QLab.4" to tell front workspace
try
set thecue to last item of (cues whose running is true and q type is "audio")
set the selected to thecue
end try
end tell
So every time you press the spacebar (or any other trigger assigned to the Group cue GO) the Main cue list will GO and the script will place the playhead, and therefore the focus of the inspector on the last audio cue that was played.
Workspace (no Audio) and example screen recording attached:
Mic