Sample size = 1 at this point, so take it for whatever you think it's worth, but...

On all of these partner bookings, I have manually entered my passport info during OLCI, due to the fact that I have found the Zamna thing to be useless. That has usually allowed me to complete check-in and get a "printable" PDF BP for the first (WS-operated) leg that has at least allowed me to get through CATSA. I have often then had the gate agent print the subsequent BP(s) for DL/AF/KL segments at the gate, which is usually quick and easy.

On my most recent itinerary (YYC-YVR-CDG-BLQ), I decided to try letting the app automatically capture my passport info. At the end of the check-in process, it told me that I was checked in but could not get any boarding passes until I saw an agent at the airport.

Thankfully, the priority check-in line at YYC was not busy and I was able to get to an agent very quickly (I find it's often staffed by just one person who gets tied up with someone who has a complex issue or the line is very long and it's slow even with multiple agents working. And I find this generally the same whether I'm at the A or D/E desks), and she was able to print the BPs pretty quickly. (I've found the kiosks usually don't work for these partner itineraries, hence going to see a live agent).

But on a more typical day with a dozen people in line, this could have been a considerable hassle.

This would suggest to me that manually entering travel document info during OLCI is vastly superior to allowing the app to capture it - I can't speak to everyone else's preferences, but I find my life to be much easier when I at least have that first BP and can get myself through security without needing to see anyone. Although again, n=1 at this point, so it's possible there was some other issue here or some recent change on the WS side that meant I would have had the same issue if I had manually entered my passport info, but the last time I did this was only ~10 days earlier (the VLC itinerary referenced in my previous post).