Access depth buffer (and scene color) from ISceneViewExtension::PostRenderBasePassMobile_RenderThread

The early z pass method is working, but we’re concerned about performance using it - in theory, we’re now drawing everything at least twice, even if the first draw is just a depth pass, is this expected to have large overhead?

My scene view extension is adding the full screen pass after opaque rendering, at this point the scene depth should be filled out. Is it possible to force that buffer to become available inside the scene view extension callback? Does an extra pass need to be added to make it available as a separate texture? If so, how do we do that given just the RHICommandList and View that the SceneViewExtension gets?