Layer Control Icon will not disable

VASSAL 3.6.5 Windows 10 64 bit

Possible bug with the Layer Control window. I can’t get the icon to grey out when the property expression is true. A sample module is available here:

Additionally, is there a way to make the Layer Control icon cycle between active and disabled just by clicking it? My intent is to make the Layer Control icon function in a way similar to the Hide all pieces on this map icon.

I’ve attempted this in the attached module. I’m using the Layer Control menu command “Hide” to fire a Set GP Piece trait which cycles the value of the HidePieces GP between true and false. The piece is named A0 and is an at start stack.

Ultimate goal is to allow users to define a grid row number with a GKC. This value then appears on map through a Label piece trait. The Zone location syntax reports the user input row number in the chat window.

Because the Grid text label is a piece, I don’t want it hidden, so the hide all pieces feature is not gonna work. Thus, I’m using the layer control feature to cycle the pieces layer between active and inactive. It’d be great if the Layer Control icon would grey out when the pieces layer is inactive. This would give users a clue why their pieces aren’t showing.

I’ve got everything working except the cycling of the Layer Control icon.

Thanks for your help.