I don't believe BXP1 require reticketing. In fact I think AA specifically does not allow a BXP1 ever to be reticketed. An SWU upgrade (which is treated almost the same as BXP1 upgrade on the list) does required a reissue. It used to be that an EP SWU was the highest priority on the u/l followed by miles and BXP1 upgrades then by 500 mile upgrades....These days I don't think anyone really knows how it actually gets pushed around in the various systems....