you can try but we also sent them some additional docs right after sending our application package but they returned our package with a letter stating " dont send anything until we request"
they did not open my second package but returned from outside
in my opinion you should wait for first stage approval and send these docs to your visa office. if your docs are expiring within 3 months, you can try sending now
or maybe after getting AOR (if there is any) and if they return your docs from Mississauga, you can send to VO later
best of luck