Physics.Simulate every frame

Unity Engine
1

I have a gameobject, when player chooses force and direction there are drawn lines of movement trajectory and end position using physics.simulate. If I use it every 0.5f seconds it works well, but I have to predict trajectory and end position every frame, but then the game is lagging. How can I predict trajectory and end position every frame?

 private IEnumerator destcor()
    {
        while (true)
        {
            yield return new WaitForSeconds(0.3f);
            touchhandler.listofcoll.Clear();
            touchhandler.force = (float)Math.Pow(distanceToRoller, 3);

            touchhandler.RollerMove();
            endpos = touchhandler.CheckPosition(rollerobj.GetComponent<Rigidbody>());
            destination.transform.position = endpos;
        }
    }

 public Vector3 CheckPosition(Rigidbody defaultRb)
    {
        Physics.autoSimulation = false;
        defaultRb = GetComponent<Rigidbody>();
        Vector3 defaultPos = defaultRb.position;
        Quaternion defaultRot = defaultRb.rotation;

        float timeInSec = timeCheck;

        while (timeInSec >= Time.fixedDeltaTime)
        {

           timeInSec -= Time.fixedDeltaTime;
           Physics.Simulate(Time.fixedDeltaTime);

        }//end while

        Vector3 futurePos = defaultRb.position;


        Physics.autoSimulation = true;

        defaultRb.velocity = Vector3.zero;
        defaultRb.angularVelocity = Vector3.zero;

        defaultRb.transform.position = defaultPos;
        defaultRb.transform.rotation = defaultRot;

        return futurePos;

    }
2

You may use separate physics scenes, like in the example in this blog post:

A hello-world style example on using multiple physics scenes is here: