Toddler I use that for my single layout games. In which case I stop the game(time scale to 0), create the sprite (making its own time scale 1.0) trancision to black or from black depending on what I need. when its gone I continue the game. Since its the same layout it just flows the movement from where it was with the backgrounds changed and clean slate for enemies.
However it is entireley possible for multiple layouts to do the following. At the end of your layout you create "Blacktrancisionsprite2" (which trancisions using fade behaviour to black ) when done(on fade-out finished) you just go to the next layout which would have the a "Blacktrancisionsprite1"(which trancisions from black to transparent (and is destroyed)
Since the sprite is destroyed when fade out is done ... or by command if you want you make sure its out of memory (if your game is dependant on that) Also since its just a black square it doesn't need to be too big just scale it as needed in the layout.
That's how I've been doing it altho I did like the layer solution I usually reserve my events for things that are not usually included in behaviours already.
I hope my explanation helps a little.