Depends on the show as previously discussed, Springwatch was recently on 23.5e unencrypted and had the directors audio on one of the feeds
A previous year's Springwatch had director's talkback embedded on one of the audio tracks, to get it back to one of their contribution OBs. A certain model of model of Freeview receiver ignored the fact that there was no control track, and mixed it in to the programme as if it were Audio Description. It just so happened that a friend of the production team had that model of receiver (and AD turned on), so it got fed back and fixed pretty sharpish!
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