The ability to make a layer within a piece invisible to non owning players/sides would be very useful to me. Some games I am playing with have command units whose identity is kept secret from the opposing side. In the physical game this is accomplished by having individually ID’d counters and keeping a list of which pieces are commanders, or have other special traits. In Vassal modules I am implementing the special trait with a layer, then covering that layer with a mask. That seems to be a clumsy solution. The ability to make a layer only visible to one side and not the other would be more elegant.