My mot man is also my re-mapper, he did a 140 to 170 remap on my old A4 BKD, that was interesting, changed that car , now got a 170 stock PD A4, that he has mapped up to 215 hp, that is great, but you have to be careful in lower gears as it lights front tyres up !! He is Celtic tuning registered, using Kess V2, he is saying now that the whole obd port upgrade is in decline, ECU's now have to be physically removed and updated on a bench, he, like you, has also had maps that have introduced driveability issues, these maps are so fine tuned nowadays, not sure re-mapping on a modern motor is such a good idea,