From the looks of things, it appears that Construct seems to render effects even if the object is off screen.
I noticed this when I added objects with effects applied to them. When I added more over the layout, things began to run quite slowly...
Also, found another bug... If you activate an effect in the event sheet editor, it will try to activate it even if the proper pixel shader model isn't supported and Construct is set to deactivate the unsupported effects, the runtime crashes...
Can be tested using both Construct's simulate shader feature, as well as forcing a certain shader model via the video driver...