Alt-arrow up/down is disabled when using a Percussion clef with a non-percussion instrument. Maybe not a situation that comes up for most, but for drums I often end up using one staff for playback and a different staff for display. When using the display staff with the percussion clef, Alt-arrow up/down is disabled, so it would be great to be able to use it to move notes up or down just like any other instrument. Thanks for considering!
This is not as simple a request to fulfill as it might appear, because Dorico uses the prevailing clef to determine some of the important information it needs in order to calculate the updated pitch of the note. But I’ll make a note of this and perhaps it’s something we’ll be able to address in future.