My and my wife's final timeline for Transit visas:
5/31 - Submitted online TRV for Transit visa for both of us
6/21 - Request for additional docs received - Employment Letter for me; Employment Letter and proof of funds for my wife
6/21 - Uploaded all docs for both
6/21 - Passport request received for wife, not for me
6/25 - Sent email to LA inquiring about status of my visa. They responded a few days later to contact Ottawa.
6/27 - Sent email to Ottawa inquiring about status of my visa
7/2 - Got back a general response from Ottawa that they will continue processing my application, but cannot say how long it will take.
7/2 - Submitted a new application for my visa with copy of old passport etc.
7/3 - Responded back to their email saying that my wife had already received her passport request and asking if I should send my passport with it too.
7/10 - Got a response to this email saying that the passport request letter (for 1st application) had been sent to my CIC account. I think the email I sent helped as they responded to the email as well the same day I got my passport request email.
7/17 - Got PP request for 2nd application as well - of course, I did not have to use this.
7/20 - PP sent to LA
7/22 - PP received at LA
7/24 - USPS return activated
7/25 - PP received
A lot to go through for a simple transit visa. If I had known about all this earlier, I would have chose a different route.
But at least I received a response to all my emails, and LA final stamping was very quick (2 days). 2nd application got approved pretty quickly as well (15 days).