Not international, but...

Flew Toronto to Fort Lauderdale this week, returning this afternoon.

Toronto to Lauderdale, from T-3. I asked at the check-in whether I had to remove the lock on our suitcase, and was told not to do so,

Fort Lauderdale to Toronto, from T-4. Told to remove the lock before the suitcase was scanned before it was sent to the conveyor to the baggage room. Note that the scanners in FLL are beside the check-in desks (at least at T-4). I asked the TSA lady if she would put our locks back on the suitcase after she had it scanned (they didn't need to open it after the scan), and she did so without any problem. We wouldn't have been allowed to put the locks back on after the scan, but she did so as we watched. Also noticed that they had a supply of those plastic tie-tags available at the scanners had we wanted them.
As to the long security lines, and taking off our shoes and boots.........another story, but no major delay or problem.

bj-21.