Thanks for your enquiry.

The behavior your describe is by design: Stationery will not overwrite an existing subject because the user may want to include that subject.

How important is it for you that Stationery overwrite the subject, or is it simple enough to clear the subject before applying stationery? It is possible to add a setting/hotkey that makes Stationery behave this way.

Regards,
Advansys Support