It not the same question. That one is about changes (rebooking) before day of flight; this one is about changing at the airport on the day of flight.

This one is a YMMV. I have been successful sometimes; other times not.

Get to the Business Lounge early and politely ask if it were possible to travel on a earlier flight. They may or may not accede to your request.

Best not to have checked luggage.