I would like to up this feature request. It'd be great to have the minimum pixel setting for line spacing within the MIDI Editor grid. Currently, this option only exists (or applies) for the arrange grid.
Maybe link the minimum pixel for line spacing to the MIDI Editor grid as well.
(Here line spacing is 2 pixels)
(MIDI Editor probably default to 8 pixels spacing)
This would be especially useful when using Notes Length=Grid, right now with the way the MIDI Editor handles line spacing it can lead to inconsistencies between what the grid shows you and what note length actually gets written down.