Both Earfonia's suggestion from Oct 9, 2019 and Tybot's suggestion from May 14, 2023 are very useful in combination: the output switcher gives you a drop down list from the available output devices. But still you have to find the device you need from that list. With custom buttons you can nail a specific device to a button. The output switcher then shows the active device.
You can search the Internet for ico's (16x16 .ico).
Even after so many years this topic has proved to be useful.
Thank you all for your suggestions.