Rigidbody and character foot placement/slippage

I think I found a solution. First, it matters how your animations are set up. For instance, some work better with "Root Transform position (Y)" based on Feet, others work better with the baked original animation.

The real issue is the foot slippage, and it has to do with friction, namely that between the collider and the ground. For individual objects it works to just add the "ZeroFriction" Physic material to the collider, but if you want to do it by script so that all your prefabs will use zero friction, just add this to your main controller script:

     public Collider col;
 
     void Start() 
     {
         col = GetComponent<Collider>();
         col.material.dynamicFriction = 0f;
         col.material.staticFriction = 0f;
     }

There might be better ways to do it, but so far I didn't find any.