I'm traveling (fully vaccinated) PDX>DFW>LHR>WAW on Oct. 7. If I travelled today I would be required to get a Covid test to transit LHR (but not to enter Poland). The UK govt has announced that as of Oct 4 you no longer need a test to transit through there. I don't really want to go to the trouble/expense of getting tested if I don't have to. I'm a bit concerned that since this requirement changes a few days before my departure the clerk at check in might give me a hard time. AA directs you to Sherpa for to check on travel requirements. Can showing what Sherpa says at check in counter get around any issue I might have in them not being aware of rule change? Does AA staff use Sherpa to check requirements or do they have a different means?