We did Thailand and used Cathay with AA miles. We went First but the details are the same. We wanted a stopover in Hong Kong but AA does not allow stopovers outside the country.

We booked the outbound JFK-HKG-BKK. Used BA miles to go BKK-HKG and then a separate Cathay ticket HKG-JFK

But like you said, we heard about AA allowing stopovers in the US. We have a trip to Palm Springs next week so i called AA and asked if JFK could be a stopover with the final destination LAX and it was no problem - basically a free First Class ticket to LAX from NY! I don't see why you would have any problem.Truly feel like I got something for nothing.

And BTW - arrived JFK January 30 and departing for LAX on May 2nd! Some stopover!