Change camera viewport rect, avoid SceneCapture2D

I’m making a game with a split-screen view. I have it working using a RenderTexture and SceneCaptureComponent2D but I’m worried about memory usage. I’d have to use a 4096x4096 uncompressed texture to support a 4k monitor (as far as I know).

As an alternative, is there a way like in Unity of being able to change how the camera is drawn on-screen and avoid the use of SceneCaptureComponent2D?

There experimental viewport widget in primitive category in UMG but im not sure how to enable them

There Slate viewport widgets too ofcorse