I don't know if this is possible or not, but I figure I'll throw it out there.
Let's say we have a screen that has a lamp FFC. The player goes to this lamp, pushes an action button, and a layer is displayed that makes the screen turn dark.
Or, alternatively, Link goes to talk to an NPC FFC, pushes the action button, and the layer with the character's portrait appears along with the text.
Basically, here's my request: is it possible, through a script (or even a ZQuest feature that I'm not aware of) that allows the player to determine when the layer is displayed? Currently, the only way I know to make this illusion is to use instant tile warps with identical screens.