How can I add a player to a layout for only some of the flows?
If you don’t want a player to play in a flow at all, in any layout, then untick the player from the flow (or untick the flow from the player) in Setup mode.
If you want to hide a player for a flow in a specific layout, add a Manual Staff Visbility change at the start of that flow: you can do this from the Edit > Staff menu or by creating a System/Frame Break and double-clicking it. Uncheck the staves belonging to whichever player and hit OK.
thank you Leo!