Not the person you asked, but here's a video you might like: https://www.youtube.com/watch?v=LNidsMesxSE&t=268s

In that example, they do the character's physics first (just a ball), then match the animation to it. The animation speed is controlled by a "surveyor wheel" approach — go to to 336s in the video for that part.

So, the animation speed is derived from the physics, rather than the physics speed being derived from the animation.

I wouldn't call that "IK" exactly, which would be more for things like matching the foot to individual stair steps as the character walks up them, or such. But I suppose in a broader sense it is, since you're deciding on a physical goal a-priori, then forcing the animation to match that goal.