Originally Posted by sannmann

When you call to apply the upgrade request, you should ask that they split the segments. Yes, you'll get more miles from the flights, reflecting IAD-NRT-BKK versus IAD-BKK; however, splitting the segments will allow you to get the upgrade if R class becomes available on either the IAD-NRT to NRT-BKK segments. If you don't split the segments, you'll only get the upgrade if R class becomes available on the IAD-BKK. There should be no additional charge to splitting the segments. Plus, the cost of the upgrade is still 20,000 miles from IAD-NRT-BKK versus IAD-BKK.