Originally Posted by
FlyerBeek
Sure, but this is not really relevant here as the OP requires GUCs to upgrade both international segments.
I am flying DTW-NRT-SIN in January and need only 1 GUC for both flights. I agree that if one segment clears the GUC is gone, so I always attach the GUC to the DTW-NRT segment and when (if) it clears the same GUC can attach to the remaining NRT-SIN segment. Even though the NRT-SIN segment is a long flight, I don't waste a GUC on a 767.