Update addOnChange.md

Author: stjanovi

powerapps-docs/developer/model-driven-apps/clientapi/reference/attributes/addOnChange.md

@@ -21,6 +21,9 @@ search.app:
 
 Sets a function to be called when the **OnChange** event occurs.
 
+> [!NOTE]
+> If addOnChange is used in a form OnLoad event handler, you should ensure it's called only as much as necessary. You can use [getEventArgs](executioncontext/getEventArgs.md) to conditionally call addOnChange based on the data load state.
+
 ## Attribute types supported
 
 All