My understanding is... you can land in each airport only once, per direction. So, the second time on Oct 2 does not count because it is after the Destination Theoretically, my return ticket could be YZR to YYZ, KEF, CPH, etc to SIN.

But a second point to note is that YZR only connects to YYZ. So if my DEST had been YYC, I believe they would have to allow me to travel to YYZ twice anyway because there is no other option to get to and from YZR. But I'm only speculating on that. And it may need to get manager approval or something.

Though I've read lots, this is my first mini RTW, so I'll defer to experts in all cases of discrepancy.