Rendering 3 viewports

I would like to split UE4 render window into 3 as shown below:-

I am wondering what is the best way to do it… there are 2 options that I am aware of so far:-

  1. The easiest… use two SceneCapture2D and the corresponding Widgets. Both are used for the left and right tile as shown in the picture above. The pink one will be the main render window.
    Pros: Easiest…
    Cons: Probably slow as it is not doing efficient rendering there. As per my understanding, UE4 doesnt have a way to render smaller rectangle within the render window (I am not talking about render target here). The pink tile is therefore, rendering at full size render window which comprised of three tiles above. And tile 1 & 3 are obscuring the render window - so it is waste here.

  2. Use SplitWindow by spawning additional 2 local players. I can get the tiles shown correctly as above, but I cannot figure out how to control the position and rotation of the camera for all splits. And plus, I read somewhere that the tiles are also not rendering efficiently.

So the question is

  1. Can the option (2) be solved ie how exactly can I control position and rotation of the camera for the splits? I think currently, the camera is positioning itself against the local player in ‘follow mode’. I am not really sure about this as information about this is pretty scarce.
  2. Can I limit the main render window to render only portion of its screen? Any code sharing is greatly appreciated even to the extend of modding the UE4 code .

Thank you.

Update: I have now got myself setting up the 3 screen using the approach (1) above.

However, I am still all ears for solution (2) ie how can I have full control on the camera transform for each split.
Any pointer is greatly appreciated.