Thanks for this. The trouble is it does not give me the option of "stereo".
I can change to 6 mono, 3 stereo or stereo plus 2 mono plus stereo.
Additional changing these options on the imported clips does not seem to affect the audio in the multi cam clip I have already created. But also interestingly it will not let me change the setting of the audio in the multi cam clip.
So I guess I have to take those clips and make a new multi cam clip with the audio setting changed on the original clips?
However I would like t make it stereo ideally. I wonder if there is a way.
You can select all the clips from the same angle within the multiclip, go to the audio tab, open up the channel configuration and uncheck all unnecessary channels. Maybe your multiclip will then be able to be set to stereo. If that doesn't work maybe you can upload an FCPXML of the event or project for us to take look at (shouldn't matter that media will appear offline).