Well, can only give you my experience.
When we went over, the incoming flight was delayed an hour, and on the return trip it was delayed two hours, so accumulated lost time....
But the impact of that might have affected my queueing and lounge experience.
1) Being in Upper, we were off first. There was still about maybe 50 people ahead of us at the various passport checks when we arrived, so probably from previous flights.
And then it stopped. Nothing moved for an hour. Not a single person at passport control queue was let through. Nothing at all. Queues built up, not sure if other flights came in, but if VS came in behind a big flight caught like this, I doubt I'd be seeing the passport queues at all....
That could be affected by the 1 hour lateness....
Once through, the luggage was all sitting waiting. It could have been a luggage check before people let through on passports. There was evidence both of ours were opened and checked.
2) Lounge on the return was ok, Priority Pass one, but the first one I've been in where they enforced the 3 hour before departure rule, which was a bit of a git since we were delayed two hours (and due to its being departure time after delay, and VS usually calls an hour before the real departure, really on 2 hours in there). So we went and hung about for an hour, had some lunch at the overpriced Margaritaville, and eventually got in.
3) Weird little final note of lateness. Pilots tend to try and use the jetstream to gain time (I think, no expert), so quite bumpy and turbulent on the way back. Only comparison I have is another 2 hour delayed one from Vancouver, which was as bumpy.