Does Scene Capture support opacity in Feature Level ES2 ?

Hi, there:

Scene Capture is improved is 4.13 and new capture sources are supported, among witch "Scene Color (HDR)" i care most as it writes opacity to alpha channel with which i can alpha blend with some other things.

I select "Scene Color (HDR)", it works fine, inverted opacity is successfully written to alpha channel of the render target( feature level SM5). But when i switch to feature level es2, alpha channel is not written with opacity. As es2 uses forward renderer rather than deferred renderer, i wonder if new features of Scene Capture are only supported in SM4 and above?