14 hour layover in April 2019/LAX-PVG-KMG-KVM

Hi, I have a stopover in PVG (which I'm not planning on leaving the airport) and then a 14-hour stopover at KMG, which I'd like to leave the airport. Am I eligible for the visa-free transit? I arrive a bit after midnight (12 am). Is the desk open at that time to obtain the document for leaving the airport?