Thank you for the details!
Castrol Edge EP 0W20 carries the MB229.71 and C5 which is safe for the catalyst.VW 508.00/509.00 is not the best approval. MB 229.71 is hands-down the best.
Ultimately, how premium an oil is determined by its resistance to oxidation, which in turn determines its performance in virtually all areas, especially the longevity and deposits. That said, MB specs champion oxidative performance with a plethora of tests. In comparison, VW specs have minimal tests for oxidative performance.
One common feature of these oils is that their ZDDP content is around 850–900 ppm, which is higher than the ILSAC limit of 800 ppm. That's why they don't get ILSAC approval and why they are not recommended for American and Japanese cars, which put emphasis on emissions and catalytic-converter endurance.