Is it possible to capture a 'free' parent transform, make it into a child, and then move it with the parent?

I'm trying to connect a player to a platform in order to make the player rotate with it. However at the moment I haven't had much luck. The platform already has a detection collider that determines when the player can turn on it, using a invisible cube. However, the platform itself needs to sense the player over it's entire surface. I'm trying a SphereCast but it isn't always working.

     // Update is called once per frame
     void Update () {
         if (_enableCapture)
         {
             RaycastHit hit;
             
             Ray testRay = new Ray(transform.position, Vector3.up);
             
             
             
             if (Physics.SphereCast(testRay, 3f, out hit, 3f))
             {
                 
                 Transform testHit = hit.transform;
                 checkCapture(testHit);
             }
             
         }
         
     }
     
     void checkCapture(Transform _obj)
     {
         if (_obj.tag == "Player")
         {
             Control _tagged = _obj.GetComponent<Control>();
             _tagged.AmbientSpeed = 0;
             
             _obj.transform.parent = transform.parent;
         }
     }

The Player is composed of three children, two colliders and a camera. I don't know for sure if parenting the player body will parent all of the children. It gets a little more complicated because after the flip, the parent needs to release everything and allow motion again.