' Возвращает True, если текст полностью виден в фигуре ShapeName
Function CheckShapeText(ByVal shapeName) As Boolean
  With ActiveSheet.Shapes(shapeName)
      CheckShapeText = (.TextFrame2.TextRange.BoundHeight + .TextFrame2.MarginTop + .TextFrame2.MarginBottom <= .Height)
  End With
End Function

Sub test()
  Debug.Print "Textbox 3", CheckShapeText("Textbox 3")
  Debug.Print "Textbox 1", CheckShapeText("Textbox 1")
End Sub