Hey folks...

I've never really played around with Expert Flyer or Expert Mode on United and I'm trying to figure out some stuff. I'm happy to do my own legwork and do some research and just generally NOT be a Pain in the Butt, but - in the meantime...

I'm flying November 7 from YYZ (Toronto) to LIH (Lihue, Hawaii), via IAD and LAX.

I'm a Platinum, flying on a fairly low fare. My itinerary is:
UA 6198 - YYZ to IAD
UA 2111 - IAD to LAX
UA 1227 - LAX to LIH.

If I redeem an RPU right now, the only upgrade I'm guaranteed is Toronto to Dulles. Would I forfeit the RPU if the "long legs" don't get upgraded, because I used it on the short leg?

What are my odds of a CPU?

And what's the best way to figure this out for future reference so I don't need to bother folks?

Any advice is gratefully received.