The specific process of connecting flights, where is the luggage?

Is it a connecting flight of the airline? If so, the ground crew who got off the plane and picked up the plane can explain the situation and follow him directly to the transfer counter for transfer procedures. If not, and the terminal needs to be changed, you need to check in again.

You can carry more than 20 kilograms of luggage with you, but you can't have liquid or metal items that you can't carry with you.

That would be much easier. All you have to do is go to the transfer counter to check in for the next stage, even if you have checked your luggage.

Walk around the terminal in 4 hours, or rest at the boarding gate.