Dorico Pro shows only one marking for instrument changes with a short duration between old/new instruments. You can choose whether warnings or labels are shown for quick instrument changes in each layout independently.
Procedure
Press Ctrl/Cmd-Shift-L to open Layout Options.
In the Layouts list, select the layouts in which you want to change the marking shown for quick 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 When instrument transitions are close: