I've flown CI SFO - TPE - BKK and return once or twice a year for the last 6 years or so. I always reserve a seat on the upper deck, but get to the airport plenty early and request a seat in row 10, the exit row. From what I've been told, they are not blocked for preferred customers, but so that the gate agents can make sure that the people who are assigned to that row are capable of opening the exit door if necessary. That said, every time I check in at SFO and request a seat in row 10, the gate agent goes to the back, a manager pops his or her head out to look at me, and I get row 10. Likewise, when I check in at BKK for my flight to TPE (continuing to SFO), I always request row 10, and it always comes through.

Arriving early may help my chances. In any event, good luck!