Achieve this same effect without needing an object in the background.

I’m trying to create a way for the player to press a button that transports them into another version of the level. My idea is to use a SceneCapture and Post Processing Material to create the initial transition, then teleport the player to the other version of the level, then remove the transition effect to give the illusion of a seamless transition between level versions.

I’ve gotten the basics of the transition effect to work and I’m really happy with it, however there is an issue I’m facing. The post processing material only projects the SceneCapture onto objects within the scene, meaning that if there isn’t anything in the background, it looks completely wrong.

Without objects in background:
without

With Plane in background:
with

Post Processing Material Node Setup:

Is there any method I could use to fix this issue without having to go about achieving this effect a different way? I’ve spent days trying to figure this effect out and finally got something that works well albeit with this issue. Any and all help/suggestions would be greatly appreciated.