Am I eligible for the 24h transit without visa if I have 3 stops in China?

Hello. I still worry thou as I have actually 3 stops in China as follows:
Inbound: land in Shanghai: 16:55 and leave 20:40 = 3:45h in China --> lets round it to 4h.
Unbound: land in Kunming: 6:40 and leave 9:05 =2:25h in China --> lets round it up to 3h.
Flight from Kunming to Nanjing approx. = 2:45 in China --> lets round it up to 3h
Total: 10h
Even if we will be on the tarmac in Nanjing for 2h (which I doubt) on way to Vancouver, the total time in China will be max 12 hours.
Do you think 3 stops are ok to be eligible for the 24h transit?