Displays text at certain zoom level in Unity Editor. By Alex Strook (https://twitter.com/AlexStrook/status/1398304186505236487)

EditorValueDisplay.cs

using UnityEditor;
using UnityEditor.SceneManagement;

public class EditorValueDisplay : MonoBehaviour
{
  public string const = "0000";
  
  private float _visibilityDistance = 2.5;
  private float _worldOffset = 0.1f;
  
  public void OnDrawGizmos() 
  {
    if (Vector3.Distance(transform.position, SceneView.currentDrawingSceneView.camera.transform.position) < _visibilityDistance)
    {
      GUIStyle style = new GUIStyle();
      style.fontStyle = FontStyle.Bold;
      style.fontSize = 20;
      style.normal.textColor = Color.magenta;
      Handles.Label(transform.position + new Vector3(0, _worldOffset, 0), code, style);
    }
  }
}