doing round trip BOS- LHR, booked via AA - flying AA out and SWU already cleared - way back is BA metal - in economy - is using a SWU upgrade worth it to PE? Incremental taxes also apply for PE upgrade or just business? Does BA do upgrade offers to PE like AA, i.e. could I pay to upgade to PE and then try to use SWU for business? First time in BA metal in ecomony and not really sure how to navigate it, appreciaet the help!