Both the Player hand and Private window can be defined to “not be visible” to players that don’t have access to it.
right now, when that option is set to “not show” to other players, the button is still visible in the menu but greyed out. Since the button is not usable by other players, it feels redundant and a waste of space having it in the toolbar visible.
My suggestion is to actually remove such buttons from the toolbar of the players that don’t have access to those private windows.
You can achieve this effect in a roundabout way:
Hide all the Private windows under a toolbar menu with no icon.
Make a global key command button with generic private player window icon.
Have the GKC trigger a hidden control piece that triggers a Hotkey that opens/closes a private window according to the PlayerSide that clicked the button.
But yes, it would be nice if you could just check a box in the editor.
opens/closes a private window according to the PlayerSide that clicked the button.
Is that something that I can do in an automatic way, using expressions or logic?
How can I do it without having a button for each specific command I want to trigger?
I don’t understand the question. You can do it the way I wrote. I don’t know of any other way within the Vassal editor.