The reason for this you can read at https://www.autoitscript.com/forum/topic/196727-set-microphone-for-playback-device/ Runs on it's own without user interaction needed. When you "Select a playback device", it will select the   corresponding microphone, or leave it as is, if one is not matched. It was coded on my PC ( a Windows 10 ), I have no more PCs to test if  it will work on other configurations but by right-click the tray icon,  a context menu will give you the option to