I guess what you guys might get wrong is how the scale is intended to work (if I am not getting it wrong):
Instead of rendering the whole image at a lower resolution, the frame buffer is masked with some kind of checker-board/chess board, which means like 50% resolution means only every second pixel is actually rendered.
The next frame, the other pixels are rendered. That way you actually have the full high resolution at the cost of “fps”. Having a scale of 50% is like running at 30FPS, since the actual full screen is only updated half the native fps.
Then clever temporal AA techniques come to use to reduce differences for quickly changing outcomes or you could always have the actual output 2 frames behind. That way should roughly be how rainbow six does it to great avail (I don’t notice a difference, you probably can only see it in fast moving scenes if you record it and then in slow motion pay attention to those screen parts)