For reasons which I cannot determine, even with research online, VW decided to use the most complex of relays for a simple tried and true function, in the simplest of vehicles. Emergency flashers typically use a simple relay. Turn signals typically use a simple relay. Bosch made millions of these for German vehicles. The 12 volt Splitties use a large Hella relay which combines these functions and the indicators in the Speedometer guage. They also devised an interesting method to allow flashers to work with the key on or off, while the turn signals only work with the key on. There are many terminals and several are very close to their neighbor when populated. While a relay is a good way to do this, this seems like an answer to a question that nobody asked. The prior solution of one or two cheap simple relays was very reliable. In any case, the big relay is a pain to troubleshoot and expensive to replace.
In this case, the Wolfsburg West replacement is not identical to the old Hella unit. It produced a fast flash and did not remedy the issue with the speedo indicators not working. In addition, the regular turn signals became unreliable. I ended up replacing the old one and deciding to tackle the issue some other day. I am tempted to unengineer this, but I want to leave the Bus stock.