Add Neutral-Sharp and Neutral-Flat to accidentals palette
Copied directly from forum thread with the same name:
"This is something that I've seen in plenty of sheet music, but I'm not entirely sure if it's still notation used today. In a score with a key signature outside of C major / A minor, whenever the sheet uses a double-sharp or double-flat and then a single-sharp or single-flat of the same note in the same measure, it is notated by placing a neutral followed by the accidental. So, a sharp note would have both a neutral and sharp accidental in front of it, and same with flats. So, is it possible to do this in Musescore? If not, then I'd simply request them as either a style setting or just their own accidental. I've seen this notation used from Rachmaninov to Beethoven, so I know it's not uncommon."