Any advice on how to dampen joints when they reach a rotation limit?

I have to say, I absolutely love this package. The layout/design of putting together rigs is awesome, performance is incredible, and overall it is my favorite addition to Unity.

I'm currently working on a motion capture solution using IK goals parented to Vive trackers, but I'm finding there is some unnatural popping when my joints hit their maximum rotation (say, a leg straightening out all the way). I assume that the best way to smooth this and create a soft limit would be to create some kind of custom joint, but I was wondering if anyone had any advice on how to dampen or slow the rotation of a joint only when it is past a certain rotation threshold on a particular axis?

I'm new to C#, and completely unfamiliar with ECS, but was hoping for some pointers to set me in the right direction. Thanks everyone, and Happy New Year!