You can arrive at the boarding gate 15 minutes before takeoff! China Southern Airlines has cancelled the check-in deadline for the Beijing-Guangzhou route.

China Southern Airlines has introduced its "15-Minute Boarding" service on round-trip flights between Guangzhou and Beijing Daxing  International Airport on top of the "China Southern Air Shuttle (南航快线)" service, starting July 8, in a bid to optimize travel experiences for passengers.
Under this new policy, the airline has scraped the previous check-in deadline for passengers with no luggage to check in, allowing them to get onboard as long as they clear security checks and arrive at the boarding gate at least 15 minutes before departure.