You can show instrument changes either after the last note in the old instrument or before the first note in the new instrument in each layout independently. You can also change the positions of instrument change labels and warnings.
Procedure
Press Ctrl/Cmd-Shift-L to open Layout Options.
In the Layouts list, select the layouts in which you want to change the position of instrument changes.
By default, the layout currently open in the music area is selected when you open the dialog. You can select other layouts by using the selection options in the action bar, clicking and dragging across multiple layouts, Shift-clicking adjacent layouts, and Ctrl/Cmd-clicking individual layouts.
In the category list, click Players.
In the Instrument Changes section, choose one of the following options for Instrument transition position:
After last note in old instrument
Before first note in new instrument
Choose one of the following options for Instrument change warnings position:
Snap to notes
Snap to nearest barlines
Choose one of the following options for Instrument change labels position:
Snap to notes
Snap to nearest barlines
Activate/Deactivate Show instrument change label after cue, if cue precedes first note in new instrument.
Click Apply, then Close.
Result
Instrument changes, labels, and warnings are shown at the corresponding positions in the selected layouts.
Note
If the duration between instrument change labels/warnings is sufficiently small, Dorico Pro considers it a quick instrument change and shows only one marking.
When instrument changes occur mid-system, you might prefer to show the new instrument in the staff label, if it is the first sounding instrument in the system. You can change this setting in Layout Options > Staves and Systems > Staff Labels.
Example
Instrument change after last note in old instrument, and instrument change label at start of cue
Instrument change before first note in new instrument, and instrument change label after cue
