I just skimmed this thread for the past hour for the answer to this situation. My flight receipt on a UA award using CA metal says the following:

Flight into China: CA986 SFO-PEK, arrive 17:55 4 Jan
Flight out of China: CA175 PEK-SYD, depart 15:50 5 Jan

So no problems with TWOV, but...

According to the fine print in the itinerary (but NOT on the flight receipt from UA), CA175 stops in PVG enroute to SYD. And I found a few TRs saying that CA175 PEK-PVG is treated like a domestic flight, so I will "exit" China officially at PVG. Hence my real itineary from the perspective of China Immigration is:

CA986 SFO-PEK, arrive 17:55 4 Jan
CA175 PEK-PVG, dep 15:50 arr 18:05 5 Jan
CA175 PVG-SYD, dep 19:35 5 Jan

Arrive into PEK, but depart PVG 25 hrs 40 min later (according to the flight times).

So my questions:
1- Anyone have an experience with this kind of "breaking the rules" (slightly over the 24 hr allowance when "switching" chinese airports)?
2- Because my offical flight receipt says CA175 departs PEK for SYD, with no mention of the stopover, will anyone in immigration - in either PEK or PVG [particularly the latter] - care?
3- And to confirm, the whole time allowance thing is calculated on published airline arrival/departure times, right? (so it's not worth being the absolute last one off SFO-PEK to get a late entry time and rushing in PVG to get stamped out quickly).

Thanks!