OnSceneGUI event Use() ates too much :)

Hello!

I am painting on a 2D texture in Editor mode(tex.SetPixels(...)/tex.Apply()). I am painting by cells(15x15). The process is simple: I click on the cell and it changed its color. I could paint by click(one click paints on cell). But it is not comfortable. So I decided to make the following: when I hold the mouse button down the process of painting never stops until I release the mouse. Here are the code that do it:

 void OnSceneGUI(SceneView sceneView)
     {  
         EventType evType = Event.current.type;
         if (Event.current.button == 0)
         {
             switch(evType)
             {
                 case EventType.layout:
                     HandleUtility.AddDefaultControl(GUIUtility.GetControlID(GetHashCode(), FocusType.Passive));
                     break;
 
                 case EventType.mouseDown:
                     lMouseBtnDown = true;
                     break;
 
                 case EventType.mouseUp:
                     lMouseBtnDown = false;
                     break;
 
                 case EventType.mouseDrag:
                     //Event.current.Use();
                     break;
             }
         }
 
         if (lMouseBtnDown)
         {
             OnSceneViewMouseDown();
         }
     }
 
     void OnSceneViewMouseDown()
     {
         Vector3 mousePosition = Event.current.mousePosition;
         Ray ray = HandleUtility.GUIPointToWorldRay(mousePosition);
         mousePosition = ray.origin;
 
         if (dg == null)
             InitDebugGrid();
 
         dg.GridCellPaint(mousePosition, passabilityRate);
         Event.current.Use();
     }

However, this Event.current.Use() ates too much. If I move the mouse across the scene with mouse button down I will not see any result on the screen until I release the button. If I remove .Use() the result of painting would be immediatelly drawn on the screen. But If I remove .Use() also I would select the texture in Scene View. I wonder if there is a possibility to do manual redraw of the SceneView ?

Thank you.