Select multiple sound output devices?

This might be a bit out there, but I'd like to select multiple sound output devices. Like multiple bluetooth speakers / headsets.

I did find the following solution, where you install `paprefs` and add a virtual output device that will output to "all local sound cards" but this gives little control, it for example also includes my laptop speakers.
https://askubuntu.com/a/78179/519324

UI wise maybe a "Output to multiple" checkbox could be added and the radio buttons could be changed to checkboxes.

This idea was also shared in: https://github.com/elementary/switchboard-plug-sound/issues/20

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