Correct me if I’m wrong, but it seems the quickest way to copy midi events (like ‘notes’) from one track to another track from the project page is:
- From the project page, select both tracks and open them together in key edit,
- select and copy the data from one of the tracks.
- While still in key edit, select the other track data and paste the data from 2).
- Come out of key edit. You can remove the unwanted track if needed.