Never.

Before that, I used a TravelPro 22" Crew 4, which was slightly larger, for 10+ years, domestic and internationally (mostly to Asia, plus a few Europe trips), and never had an issue with that bag either. probably 300-400 flights, and not one single time was I asked to put it in the sizer.

IMHO, if you're nice to people (especially the airline employees), and aren't obviously taking advantage with a massively overstuffed bag, they don't care if your bag is an inch too big. It's the "do you know who I am?" types that talk down to the gate agents, who are told to put their bag in the sizer, then told with a smile, "I'm sorry sir...".

Just my 2¢.