Changed my question a little: I’ve got a regular staff for my percussion player, but would like to be able to move between treble clef (for certain percussion instruments) and the percussion clef for unpitched instruments. The instrument I created is simply a violin (but of course it has been renamed ‘percussion 1.’ My issue is that when switching to the percussion clef, the note input behaves very oddly, I can’t seem to put notes wherever I want, they don’t respond to the ‘move note’ hotkey shortcuts, and sometimes they are displaced by many octaves. Any advice? Thanks!
Put a notes page at the front of the percussion part (Engrave mode) giving a description of the two percussion layouts. Then have two pecussion kits or two orchestral players with the respective instruments. Make sure to think about physical layout, that it’s something they can work with and the instruments can be played with how you score it (e.g. not have them play xylophone and crash cymbal at the same time!) How to Write for Percussion gets into this.
Part 2 - not sure, but probably you can’t change it. Why would you want to? Consult Solomon’s book and maybe Behind Bars by Gould to make sure this is a good idea, or ask a percussionist. I’m a wind and piano player so don’t know, but generally I wouldn’t want a big layout change, instead give players consistency.