The multi-destination tool seems to just give me the same price I'd get if buying the ORD-AUS part separately (about $360 one way to Austin, tacked onto the AUS-HKG-ORD fare). I was wondering since ORD-AUS is a domestic leg and less than 24 hour layover, whether there is some way to get the system to book it as part of the same outbound flight from ORD to HKG.

On the way back: In order to fly HKG-NRT one day and fly out NRT-ORD the next day, I can't find any way to do this on UA metal without going to a >24 layover. HKG-NRT lands at 3:35, and the earliest UA flight out to the US is to SFO at 3:55 the next day. The only option to book the return HKG-NRT-ORD with a non-stopover layover in NRT seemst to be to pay $400 extra to go NRT-ORD via ANA the next morning. (This also costs me 7000 bonus miles for flying on non-UA metal.) Is there any way I can, say, buy the ticket all on UA metal with just the standard 1 hour layover, and convince an agent or somebody at NRT to rebook me on the next day's flight to ORD? I'd even contemplate just missing the connecting flight and asking to be rebooked the next day, but would feel bad about that.