Just some more idea - thinking about what you might have intended - possibly just have a thumbnail of a scene to be shown in saved games menu (like I remember when I played HalfLife 2)
So I searched for options, which could help in saving a screenshot in a SaveGame object and came across this one.
It does involve C++ and I did not get deeper into it, but it relies on a SceneCapture2D and saving data to a SaveGame - so that’s something, that is available to the player…
Just some idea, of how this could be possible…