Yes, the regulations in germany are strict, but not evil. As long as you have the EU markings on your exhaust and didnt remove your dbKiller, you are normally safe. Same with exhaust valves.
It is still possible to get a good flowing exhaust on your bike. But if the cops already hear you from miles away, your chances are not good.
And exhausts without EU marking are a no go. The cops can be as dumb as a wet fart, but they all know exactly where to look for the marking. Exhaust, light, mirrors.
If they find the markings, you are normally good to go.
Interestingly most of the Harley exhausts dont have the EU marking, but are still legal. The cops know that, so the chances are good that you can pass with a OEM lookalike exhaust.
And if you got a real exotic dancer, you can do whatever you want.