Unless i'm mistaken, ctr z only changes your joints to what they were previously.
What I'm suggesting, being able to see what you did 50 or 100 frames ago and how that visually flows into your current position, would help you keep track of your overall motion i feel like so it'd be easier to design your replays to how you want them to look.
you can do this by pressing R but its a really clunky way of doing it. Especially in long replays with thousands of frames, or if you're really trying to polish a movement so it fits in with the replay overall.