How to use ue4 backed lightning on unlit material? Cloning unlit shading model maybe?

Hi! I’m already using pre backed maps from blender to my vr game, using only unlit material (way cheaper for oculus quest). but the workflow is too slow. i’d love to just push “build lightning” inside unreal and see the changes on my unlit material.
I know this is something impossible out of the box (if i’m wrong here, please tell me).So i think maybe there is a way to clone the Unlit Shading model and copy something from lit? So this way i can select it from the Shading Model dropdown menu in the material. Where can i start searching about this?