Unet with additive scene loading and different scenes for each client

I've just started working with Unity for creating a (somewhat peculiar) multi-client game involving minigames. I'm planning to store each minigame as a separate scene, but multiple players might be running separate minigames at the same time (or even a separate instance of the same game). For this, I need additive loading of scenes, loading a single scene multiple times and loading different scenes on different clients, all while keeping the objects synchronized. I couldn't find...

Unet with additive scene loading and different scenes for each client