There does not seem to be an "Un-Split Audio" feature.
What do I mean by that?
Well, there is a command "Split Audio" which splits a clip with audio+video into separate video and audio tracks. Once done, there does not seem to be a way to later on undo that splitting. Am I right or did I overlook something?
If I am right (please give me some feedback on this) I should file a feature request accordingly.