Maybe it means compression happens earlier in the chain? For example, everyone else is compressing HDMI output and Rivvr is compressing the post VR compositor

Maybe it means compression happens earlier in the chain? For example, everyone else is compressing HDMI output and Rivvr is compressing the post VR compositor render target before scan out happens? This would break an app that does front buffer rendering, but afaik there aren't any commercially available VR games that do that. No idea what the actual difference is and I'd like some clarification also.