The Pershing II.
It had an active radar used in the terminal stage of flight, giving the Pershing II a CEP of 30m and a very effective hard/deeply buried kill capability with a warhead that ranged from 5 to 30kt.
It drove the Soviets absolutely nuts because of that capability and was one of the driving reasons behind the INF Treaty.
This technology has been around for 30 years, so don’t think the Chinese can’t develop something similar.
Once again, that’s about fine tuning accuracy when the target was already pre-determined ahead of time. It’s not about hitting a moving target.
You quote CEP numbers but I don’t think you realize what they mean. Ballistic missiles have gotten much more accurate over time, but they have no ability to track and target moving objects while in flight. If you understand the physics of this you will understand why this has to be so.