Multiple viewport frames sharing the same workspace / models

I want to design a multisplit screen on a single client by making use of multiple viewport frames viewing the same space. The intended use is for hosting multiplayer party games locally on a single computer. I want the viewport frames to act as multiple cameras (one for each player’s perspective).
I noticed some people place the model inside the viewport frame, but I’d like to avoid having to synchronize the models across viewport frames. Is there any way to do this? Are there other ways of having multiple cameras render on a single client?