I'm not sure if this would be considered a bug.
I'm using the fade behaviour. When you first run the game, the plugin seems to run through all the sprites in the layout and get their opacity, setting "this.maxOpacity" to the current opacity.
This seems to have an odd side effect: If I set a sprite to opacity 50 in it's properties, maxOpacity is set to 50 on load and it fades out correctly. However if I set the opacity through an action then maxOpacity is already set to 100 on load, causing the fade behaviour to jump from 50 back to 100, then fade out.
Does this seem like a bug? I'm hesitant to report this if I'm just missing a step.