Best way to handle Chroma Key on low spec hardware

Hello everybody,

I need to composite green screen footage over a 3D VR environment.

I’ve seen there’s a few tutorials on applying Chroma Key to a video texture and that’s ok, but having a low spec hardware as a target (Oculus Quest - Snapdragon 835) I wonder if it’s better for the performance to go this way or feeding Unreal a video with Alpha Channel

I’d prefer not to reinvent the wheel, anybody tried this approach?

Thank you in advance, cheers!