Test Unity time scale and physics rigidbody jitter

TestTimeScale.cs

using UnityEngine;
// Create a plane and a cube above that plane, attach a rigidbody to the cube & add gravity
// drop this script anywhere on the scene and watch the variables in realtime
// mess around with timeScale and see the results
// toggle the jump checkbox during runtime
public class TestTimeScale : MonoBehaviour
{
    [Space,Space,Range(0.01f, 3f)]
    public float timeScale = 0.5f;
    
    [Header("total time")]
    public float time = 0;
    public float fixedTime = 0;
    public float unscaledTime = 0;
    public float fixedUnscaledTime = 0;
    public float timeSinceLevelLoad = 0;

    [Header("delta time")]
    public float deltaTime = 0;
    public float fixedDeltaTime = 0;
    public float fixedUnscaledDeltaTime = 0;
    public float smoothDeltaTime = 0;
    public float unscaledDeltaTime = 0;

    [Header("physics")]
    public Rigidbody target = null;
    public bool jump = false;

    void Start()
    {
        Time.timeScale = timeScale;
    }

    void FixedUpdate()
    {
        fixedTime = Time.fixedTime;
        fixedDeltaTime = Time.fixedDeltaTime;
        fixedUnscaledTime = Time.fixedUnscaledTime;
        fixedUnscaledDeltaTime = Time.fixedUnscaledDeltaTime;
        
        moveTarget();
    }

    void Update()
    {
        Time.timeScale = timeScale;

        time = Time.time;
        deltaTime = Time.deltaTime;
        unscaledTime = Time.unscaledTime;
        smoothDeltaTime = Time.smoothDeltaTime;
        unscaledDeltaTime = Time.unscaledDeltaTime;
        timeSinceLevelLoad = Time.timeSinceLevelLoad;
    }

    void moveTarget()
    {
        if( jump )
        {
            if( target != null )
            {
                Vector3 f = Time.deltaTime * Vector3.up * 300;
                target.AddForce( f , ForceMode.Impulse );
            }

            jump = false;
        }
    }
}

when changing timeScale the following will

change

• deltas:
• • Time.deltaTime
• • Time.fixedUnscaledDeltaTime ( ? )
• • Time.smoothDeltaTime
• timers:
• • Time.time
• • Time.fixedTime
• • Time.timeSinceLevelLoad

not change

• deltas:
• • Time.fixedDeltaTime ( ? )
• • Time.unscaledDeltaTime
• timers:
• • Time.unscaledTime
• • Time.fixedUnscaledTime

Note: fixedUnscaledTime will start breaking down when timescale will be near zero