I unmix tail ends of live tracks, to reduce applause, hoots and hollers. If I select the last 5 seconds or so, all the way to the end of the track, SpectraLayers often adds a few blank seconds at the end of the track. Here is a comparison in audacity of the source (top) and the processed track (bottom). This happens around 80% of the time.
If I don’t select all the way to the end of the track, then this doesn’t happen.