When running the overlap detector .py via double clicking, the window will run through the list of overlaps and then close without having any chance to read them.
This isn't the case when running from the command window beforehand, but having to do that all the time is pretty bad UX.

I suggest adding either a Press any button to continue... or 'Exit program? (y/n)' prompt at the end of the script to have time to look over them.

Sometimes I have midis where the event list places the note off event after the next note on event
ie: like this (from synthfont's event list) note how event #486 is a note on event and is listed before #488 which is note off event

     # | Bar   | When  | Length|Chnl| Vel|Note|  Operation  | Data
   482 |    13 |  4848 |    24 | 10 | 39 | 44 |note on      |
   486 |    13 |  4872 |    24 | 10 | 39 | 44 |note on      |
   488 |    13 |  4872 |     0 | 10 |  0 | 44 |note off     |
   493 |    13 |  4896 |    24 | 10 | 79 | 44 |note on      |
   497 |    13 |  4896 |     0 | 10 |  0 | 44 |note off     |
   501 |    13 |  4920 |     0 | 10 |  0 | 44 |note off     |

As far as I know this doesn't have any detrimental effect on DK64's music engine, so I suggest having the program make an exception for this type of case.