Export Mixdown are stored with the song, not globally.
Which is odd, because, if you change the settings - ie from Stereo to Mono, the Save button for the song remains greyed out, to S1, nothing has changed in the song. If you close and re-open it will revert to previous saved settings.
This bugged me, I had a song that required a Mono mix down, which I rarely use. The client wanted a stereo mix down some weeks later and when I called the song up from its last saved version it defaulted to a MONO mxidown, even though another song I had loaded at the same time was stereo mix down. I changed to stereo but was unable to simply do a Save with the new status as the button was greyed out. Meaning Studio One did not recognise any change in the song.
Please fix this. Either making mixdown settings Global or recognise the change in song status by un-greying the save button when a setting is changed.