The manual says (Deleting Overlaps):
You can delete overlaps of notes that have the same or different pitches. This is useful if your MIDI instruments cannot handle overlapping events.
and
The overlapping MIDI notes are shortened, so that no note begins before another ends.
But I’ve tried this and it doesn’t do anything. I’ve tried selecting the MIDI event in the track and clicking that function, and I’ve tried selecting all the notes within the event and clicking it, but it doesn’t have any effect.
I have, say, and half-note C1 event on beat 1 followed by a quarter-note G1 on beat 2. I would expect that function to alter the C1 event so it’s a quarter-note.