There is another post about accidental display in this subforum but this particular bug is crippling, so I thought it deserved its own post.
There are very specific rules (not very complex logic) to displaying accidentals in Western music notation for verticalities (chords) whether and in what order they must shift to the left of the noteheads. Reaper ought to implement all of them, but first and foremost, sharps MUST NEVER be displayed atop each other if less than a sixth apart, because users get this situation:
As you can see, it's impossible to read whether the middle note has a sharp on it or not. In this case, the lower sharp should be shifted to the left. If a sharp came in on the middle note, it would be shifted furthest left.
MIDI Editor Notation View: Sharps (accidentals) display incorrectly in chords
Linear Mode
