I know this has been answered here - but just wanted to triple check - BXP3's work the same exact way as SWUs right? Same priority, automatic reticketing, etc correct? Literally the same instruments in the eyes of AA (assuming of course the applicable fare code has been booked to use?)

I am headed to Shanghai for the holidays and trying to upgrade from PE to J and one way is still waitlisted. I called the EXP desk who told me SWUs take priority over BXP3 which I am pretty sure is not the case. However since I will be traveling from China to the USA (on 1/1 which will be a rough day as is) I did not want to risk and swapped the BXP3 for a SWU. Was that a mistake? This was an SWU expiring Jan '20 whereas the BXP3 expires in May '19 - clearly I would like to use whatever expires first if all else is equal. Any advice here would be greatly appreciated!