I have a lot of recurring matinee cutscenes which are set in spaces the player will never access during gameplay, with characters he’ll never encounter during gameplay. I don’t want to keep cutscene assets loaded in memory all the time as that’s pretty wasteful, especially if I end up with dozens of characters and numerous rooms used in matinees. Since I’m using level streaming to ensure that the entire world is in a single continuous space, am I correct that the most efficient way to manage all of the actors and geometry matinee needs is to build the cutscene geometry in a level that gets streamed into a space away from the rest of the map, and let unreal load assets on the fly when the cutscene starts?
I dont know if there is a better way, but I personally would also do it like that -> put everything into a own level + stream it in and out 
Otherwise you could also load the map instead of streaming it, but then the player has to wait a little bit (it’s not so seamless)
Alright, thanks for confirming- it’s nice to hear that it isn’t a completely silly idea. 
This is a bit tangential, but do I need to be thinking about each matinee’s size in memory at runtime? The final project will likely include several hundred cutscenes rendered in-engine, and I’m not really sure how to assess how much of a footprint that’ll make on my overall memory budget.
When you have many cutscenes, you could also render all of them + play them as a movie when you need them (so bake mp4 files which you then use in the engine -> instead of play them in realtime)
That’ll save time for some of them, but in some cases I need to keep them in-engine for mechanical reasons- there are lots of small changes in world state that are reflected in how interior spaces look, and if I encoded a movie for every possible permutation I would end up with a video folder that was exponentially larger than the game itself.