Originally Posted by ER-One

unfortunately not. Award and Upgrade C inventory on EF only pertains to SWU availability on AA metal. EF does not support award availability searches on BA and so you have to find award availability the old fashioned ways. If you do find J award availability, as you seemed to have found for your flight in question, AA should be able to apply an SWU from PE to J. However, I think I would personally rather book through BA and use avios to upgrade in this instance than a more valuable SWU.