Thank you 9symmerty for the sharing, it helps because I am one of the people who sent the OWP app with insurfficient payment, just don't know whether I am one of the four cases that you mentioned above or I am the fifth case. :
My apps were sent in mid Nov, my visitor status expired in early Dec (I'm now in "implied status" I believe).
I think I'm not going to take any actions but wait till they get me response, because they may still process my OWP app with contacting me to supplement additional payment, or they may return my app in worst case, however based on my previous research (see my post in Page 170 or the quote below) I believe I still have 90 days to restore my status beginning from the day they decide to return my app.
Do you think this waiting workable, or it's still risky for my status in Canada? thanks.