MIDI export error: Note length error stack up when notes are tied

Related to issue #311029 (which is not really an issue)

When MuseScore exports MIDI files, notes are clipped just a little and a short rest added, seemingly for the sake of allowing varied articulation. For example, staccato notes have a longer rest afterward, slurred notes have a very short rest (from what I can tell, usually just one tick). This is fine and well, as it allows some measure of customization to the MIDI export.

The problem appears when you tie many notes together. The expected behavior is to add one short rest to the end of the long string of tied notes. However, MuseScore's export tool seems to add rests segments to the long string of tied notes proportional to the number of notes tied together. With many notes tied together, the rest can balloon to be many beats long, cutting the note noticeably short when the sound is expected to continue right up until just before the last beat of the note.

This can be readily seen in the attached screenshots from an online MIDI editor. With no ties, each whole note has a small gap following it. With all of the whole notes tied together, there is a large gap at the end much larger than the gap following each of the un-tied notes.