Transparency in a RenderTexture with the new process stack

When I add the new render stack with just antiailiasing to a camera that renders to a RenderTexture, transparency is gone. How can I fix this?

Also the temporal AA simply doesn't work, it clears the whole RenderTexture.

Edit: Even with legacy ImageEffects I simply cannot put any kind of AA on a RenderTexture without it disabling transparency. Any thoughts?