The truth is, if your first leg is CX and connecting to KA, the KA flight would sometimes be held up and wait for CX if a lot are transiting from the CX.

In the other way round, CX flight will leave as it should regardless of the KA transit.

Nevertheless, plenty of ground agents would be waiting for you to try to catch it up for you in both cases.

So, just head to PVG after your work, forget about OLCI, go to counter and ask for checking in to the next leaving flight. That's how it works in PVG (and PEK).
If you arrive early enough, you can probably squeeze into KA805 with a big rush from the counter to the gate using
all the "Emergency Lanes" at Customs and Security Checkpoint if your flight is leaving in the next 30mins or less.