Just received the PPR from LA (via e-mail to my sponsor).
A couple of interesting things to note:
(1) There is no option to present the passport in person on the letter. It states "You are required to submit your passport(s) and photographs by MAIL within the next sixty (60) days from the date of this letter."
(2) They will send a passport via express mail in the US, but only by regular mail in Canada.
I have to be in the US in mid-October for work anyway, so my hope is that I can manage to wrangle this to get my COPR back by the time I have to return at the end of October.
Surprising what a relief it is to have received this.