I use the BA engine to look up LAX-HNL, find a flight on AA in Y. "Hey, you're short Avios, please buy some."
I use the BA engine to look up PHX-HNL, find a flight on US in Y. "Hey, you're short Avios, but you can fly for only 4,000 Avios plus $100.60! Lucky you!"
Is AA blocked from Avios+cash redemptions, and US isn't?
I did search, didn't see anything obvious, also found some TPG posts that imply that this DOES work for AA...
http://thepointsguy.com/2012/05/maxi...d-cash-option/