For anyone else who would find this useful, I kludged together a little vb app (attached) that does the job.
It creates a tray icon that indicates if a device is connected. It simply runs "adb device" and reads whether a device is connected.
By default it will indicate any device connected. Put a specific devicename on the commandline if required. Right click the tray icon to see name of device found.
It updates every 2 secs so don't leave it running all the time, just when relevant.
To end app, right click icon & select Exit, or just dblclick icon.
31/07/24 added ability to map a readable name to device name. Just create TrayMonMobConnected.ini in same dir as exe or where adb.exe is.
INI should contain:
[Maps]
E2280EF=My S23
and can also contain
[Settings]
ShowDevNameWithMappedName=1 (or 0)