VST plugins not receiving note-off; VST plugins not receiving pitch bend information

Please see my video for a demonstration; it's easily reproducible

https://www.youtube.com/watch?v=DxV4IHvHHCw

1. Load a virtual instrument that sustains notes until a "note-off" signal is received; I used the popular software synth Vital
2. Begin inputting notes on the same beat at a rate faster than one per half second, or use the arrow keys to change the pitch of a note
3. The synth continues playing some of the previously inputted notes

I concluded after some testing that this is because MuseScore does not send a corresponding "note off" signal following the initial "note on", after the pitch of the existing note was modified.

By default, notes on entry are played for 500ms. I changed this value to 50ms. This kind of "works" but the bug is reproduced as soon as I input two notes within 50ms.

I tried to reproduce this problem using MakeMusic's Finale and the Vital plugin for playback; I was unable to recreate the issue. (Nor have I encountered anything like this when using a DAW with Vital)

Finally, the way per-note retuning is supported within MuseScore is impractical (which is not a bug), but also it is not supported by VSTs (certainly not by Vital).
1. Load VST such as Vital for playback
2. Input two notes on the same pitch and a third a semitone below
3. Change the pitch of the second down by 50 cents
4. Playback; note that the second note's pitch is the same as the first

Again this is thoroughly supported by other software; I used Finale and a per-note custom expression symbol (which can be added with just the press of a hotkey) using MIDI pitchbend data and this plays back exactly as expected with Vital.