My experience is about 5 years old now but may help (or at least get the ball rolling ...)

I went to Canada on a visit (including meetings with potential employers in Edmonton and Winnipeg) while my PR application was pending.

I was sent for secondary screening but it did not take long and the officer was pleasant. I flew in to Calgary and the queue was short but queues elsewhere might be longer.

I was specifically asked for proof of a return ticket and given a 4 week time limit on my entry for that trip - but I was booked to return in a fortnight anyway.)

PS The fact that I flew in to Calgary might also explain why the most pointed question I got was why on earth I might want to live in Manitoba rather than Alberta!

Good luck!