Without knowing the exact route you are after I don't know the answer. Sanya as a few unique things going on includes a few crossing route of unusual levels and directions, as well a being met by metric/imperial flight levels.
Only recently during on of the typhoons I heard Sanya go ballistic at a carrier that had not called in. and by the time they had made contact there was a loss of separation due to widespread weather deviations an aircraft coming in feet occupy two metric flight levels, they had the aircraft orbiting unable to move in any direction due to traffic. From what I could hear the crew seemed contrite but blissfully unaware that their weather deviation in the previous FIR had not transgress past the boundary into the Sanya FIR where the weather was getting worse.
I would say 98 times out of 100 I am getting handed off by 40 miles to the boundary for Sanya, that covers your 5 minutes. There are times however they forget or get busy, and then you know where the finger will be pointed. All I do is tell them the flight level and transponder code, they ask me then to report at the boundary. If I am offset due to weather deviation, I will contact them to get the deviation clearance before entering the airspace. I assume nothing in Asia.
Remember these controllers do not have flight strips being handed off from one FIR to the next, while the FIR is advised of your plan from the AFTN, they need to generate a flight strip (which maybe just electronic) for you before you enter their airspace. Then they can tag your transponder with your details so they have a flight block associated with your aircraft.
Thats great, good for you. A very large middle eastern carrier has been operating into China much longer than that and also thought they knew better. Last year the CAAC issued them demerit points and a fine. The fine was a token, around US$5000, the real killer was they were banned from adding any additional services to China for 6 months. They get more demerit points, that ban will get bigger.
If you are a business jet operators, they may simply refuse to allow entry into their airspace ever again.
https://www.bloomberg.com/news/artic...dents-in-china
This is the "Administrative Procedure" only been in force for a little over a year. A few international carriers have been caught, a few local airlines, pilots grounded, ATC sacked, airports fined, and airlines being forced to stop expanding. And some business jets refused entry ever again.
https://fsop.caac.gov.cn/files/1411-...20Carriage.pdf