So my initial working with the engine and there's no option to switch the Firefly Engine visibility off and on incase you want to see the 2D logic behind the 3D. A work around is just to move the XPosition of the Firefly Engine object off screen and then move it back to 0 this will allow you to see behind the Firefly Engine object so you can basically see how your game looks like as a Fusion 2.5 2D application. I tested this with the platformer example. Worked great.
Hope this helps.
