Add renderer to LOD via script

I'm trying to group my individual objects' LODs together into different segments of a grid to help optimize performance. I'm fairly confident my logic is sound: the grid segments have trigger colliders. When a LOD-able object enters its trigger, it runs this script to (theoretically) add the object's renderers to the grid cell's appropriate LODs:

 private void OnTriggerEnter(Collider c)
     {
         if (c.gameObject.tag == "Detail")
         {
             LODGroup l = this.gameObject.GetComponent<LODGroup>();
             GameObject obj = c.gameObject;
             obj.GetComponent<LODGroup>().enabled = false;
             for (int i = 0; i < l.GetLODs().Length; i++)
             {
                 if (i < obj.transform.childCount)
                 {
                     Renderer[] temp = l.GetLODs()[i].renderers;
                     l.GetLODs()[i].renderers = new Renderer[l.GetLODs()[i].renderers.Length+1];
                     for (int j = 0; j < temp.Length; j++)
                     {
                         l.GetLODs()[i].renderers[j] = temp[j];
                     }
                     l.GetLODs()[i].renderers[l.GetLODs()[i].renderers.Length-1] = obj.transform.GetChild(i).GetComponent<Renderer>();
                 }
             }
         }
     }

However, nothing actually happens. I went into Debug mode and looked at the grid cells' LOD groups, and all their renderers arrays were empty with length 0. I guess my question boils down to: can a script emulate the nice, clean, simple behavior of the LOD Group "Add" button?