I gave it a try... the only way I could do it with no flicker was to have the Fade sprite visible and covering the screen at the start of the layout. So, I put it in its own layer, and made the layer hidden so it doesn't cause trouble editing other things on the layout.
I added Fade to the sprite twice - once called FadeIn and once called FadeOut. That way I could have everything preset - just not enabled.
at the start of layout I enable FadeOut, so the screen goes from Black to visible. We get a trigger when that is done, so we know the game (or menu) is ready to go.
when it is time to leave the layout, I start FadeIn to go from visible to Black. That gets its own trigger, so we know when to call the next layout.
I didn't use a function or any global variables - just the triggers.