This should help on my YTZ/YYZ-YUL commuter flights where some pax board with multiple bags. It is coming in time for the winter vacation flights where cabin space is squeezed because of the coats. AC was smart not to apply the change for the Christmas/Festivus/New Year peak travel. There would have been chaos.

If AC wants this to work, they should change their ticket purchase to require an acknowledgement from passengers on the carry on rules. At the very least a very clear warning is needed. The airline can offer its useless insurance option, so it should be able to offer the carryon baggage advise. And yes, I too anticipate some people will still try to game the system with a few tantrums at the gate. Although some infrequent flyers will be clueless, alot of pax know what they are doing when they bring their excess carryons.