The Actor Palette plugin seemingly loads a different level, with its own lighting, unaffected by the lighting in the primary level*
*(I’m making assumptions, about this and other things, so could be way off).
Is it possible to load a level that never renders or interacts (physics, lights etc.) with the primary level, but can be viewed (e.g. a camera to switch to, or scene capture for use in RTT) from the primary level, and the player character moved between?