You can change an existing source (preview) without closing it.

E.g. the Side-by-Side preview is based on a black color background, but you could also replace it with an audio input, while still keeping the side-by-side multiview.

This way you can save input sources.

  • Click on the Settings icon below Side-by-Side

  • Click on Change

  • Select another input like Audio input
  • Select an Audio Device and commit with OK