Key Editor scrolling performance drops even when all MIDI data is off screen/out of view

In neither GIF there are any events drawn on screen except for one note, but the difference is that in Case A there’s a lot of out of view (off screen) MIDI data.

Case A: Lots of out of view MIDI data:

Case B: No out of view MIDI data:

This is not a drawing issue, since there aren’t more things to draw on the screen. So it might be possible to optimize this.

How to reproduce:

  1. Open the project attached to this project. (MIDIStress.zip)

For Case A:
2. Press CTRL+A to select all events in the project and press Enter to open them all in the Key Editor. Maximize it.
3. Move all the way to the right, to bar 196 and make sure no midi data is on screen except for one note.
4. Scroll the view with the middle mouse button
-> There is major slowdown even though there is only one note drawn on screen.

For Case B:
5. Open the single event on the lowest track. (bar 45)
6. Scroll the view with the middle mouse button
-> It is smooth, just like you would expect Case A to be.
MIDIStress.zip (1.35 MB)