I've searched this forum and google and only managed to dig up some very old posts, without any real solutions.
Is it possible to create a mixdown with the metronome included? By default it is muted in the mixdown regardless of mixer settings. I've tried sending it to a bus, but again it is muted in the mixdown.
If it's not possible, is there a plugin that will work?
1) Record the analog output and add as audio track
2) Rewire (software), which I haven't worked with much, but which at least in theory can combine audio outputs from several audio streams on the same computer. Since the metronome is an audio stream sent to the speakers, maybe Rewire can access it. As for if and how to get it recorded into Audition from there, you'd need someone familiar with Rewire...