Mnn, I was told by 2 FT'er that open-jaw is only at destinations and not at stop-over's
I didn't try otherwise when I booked 2 weeks ago (e.g. PVG-*-MUC, stop #1, MUC-*-YYZ, destination, YYZ-TPE, stop #2, TPE-PVG), otherwise I would've open-jaw as arriving at MUC, leaving from ZRH instead