OK so 2d/3d switching is pretty seamless (seemless?)

src/display2d.rs

@@ -46,10 +46,6 @@ impl Plugin for Display2dPlugin {
             .add_systems(
                 OnEnter(GameState::Play),
                 activate::<Display2d>.run_if(in_state(DisplayState::Display2d)),
-            )
-            .add_systems(
-                OnExit(GameState::Play),
-                deactivate::<Display2d>.run_if(in_state(DisplayState::Display2d)),
             );
     }
 }

src/display3d.rs

@@ -68,10 +68,6 @@ impl Plugin for Display3dPlugin {
                     activate::<Display3d>.run_if(in_state(DisplayState::Display3d)),
                     set_piece_texture,
                 ),
-            )
-            .add_systems(
-                OnExit(GameState::Play),
-                deactivate::<Display3d>.run_if(in_state(DisplayState::Display3d)),
             );
     }
 }