You're a VW tech if IIRC from another thread, correct?The dealer can see the TD1/TXD code before he even makes a claim. They can see is in the online tool 'elsa' where they check history and car info. There the Flagg wil be visible. When a car is scanned for normal maintaining work the engine 'life cycle' écu data is auto send to vw. Auto flagging running can take some time my old car gtd 7 got flagged after 1 year. But however if there is done some extra work the check happens instantly for example my gti is flagged within 1 min after updating mib firmware. Also the tech/dealers must start a guided programe 'waranty check' when big engine an drivtrain work is done. Then it also gets flags within minutes.