What? Your numbers are right, if you were running the game at 100FPS it would take 10ms to render a frame. Plus your 10ms of additional latency from holding the frame. 10ms + 10ms is 20ms.

If you were running the game natively at 50FPS, it would take 20ms to render a frame. That’s the same number. The total input lag from rendering is identical. Add in the slowdown from your GPU rendering the in betweens and its even worse.