I was looking to learn more about when I found this blog post which talks about the new multiplayer nodes and provides a basic example.
You can say whatever you want but this, this is gold and far faster than learning how it works step-by-step and hoping to replicate any guide. I now understand how the MultiplayerSpawner and MultiplayerSynchronizer nodes work. I just hope they’re not too heavy since replicating scenes sounds like a lot of work.