I'm flying on a CO J award ticket SIN-NRT-ORD-EWR, with the whole route on UA metal (and SIN-ORD is the same flight #.) CO's NRT-EWR J cabin has more than 20 seats available for sale...but it leaves after the NRT-ORD flight does. Could I "standby to a later flight" to get on the NRT-EWR nonstop or is it not possible to do this on a reward ticket across different metal?