iNotes - Query Save Agent for ToDo and Calendar

I have one question regarding iNotes customization - using QuerySave Agent. I got the querysave agent working in “Memo” form, using the tag : <NOTESVAR NAME={$$QuerySaveAgent} TYPE={Text} INITIALVALUE={“agentname”} in subform “s_MailMemoDictionary”.

But, I am unable to get it working in ToDo and Appointment forms. I used the same tag in subforms “s_AppointmentDictionary” & “s_ToDoDictionary”. But the agent is NOT trigerring. I tried it in v8 and v8.5. Is this an iNotes limitation OR is there a different method to make the querysave agent working in ToDo and Appointment forms?