I've been thinking about the Home Alone analysis discussion, and I think I figured something out. In the discussion, @mlucas proposed that Kevin's mother Kate was a second IC, along with Marley, but then @jhull provided the official analysis for the film, where Marley is the sole IC. According to my understanding at the time, that would mean that Kate's role in the story is completely confined to the OS, and that didn't sit right with me.
However, in light of the idea of the RS hand-off, I had an idea. What if there were two RS players in this story, both the neighbors and mother/son relationships? This would still be consistent with Marley being the sole IC, and it would explain why the RS otherwise appears so light. Kevin and Kate's physical separation from each other seems to go hand in hand with the shared isolation from family that Kevin and Marley share (RS Domain of Universe). In addition, that moment during the last scene where Kevin and Kate hug feels like part of the RS being brought into balance.
What do you think?