Can't say I'd be delighted about this, but they'll very quickly leave when the food's disturbed and wasps - like bees - don't leave behind diseases or eggs. The same cannot be said for flies - if those were flies I wouldn't touch anything in the shop.
Here it's usually that they seek out the breath because of the monoxide and people start panicking because the ly fly into their face and seemingly wont go away. So they Start swinging their arms at the wasp and it feels in danger and attacks.
Easiest solution is to hold breath and walk away if they bother you.
The waps here hang paper nests all over the place. Like outside your kids room. Maybe even inside. We mostly encounter them in the context of their breeding activities.
The nest is my primary target. Cover up, knock it down, destroy it, walk away for a bit, they all leave. Fuk wasps.
Hmm. When you consulted "every source I could find about wasps in the US" apparently you chose to disregard the direct feedback of people on the front line. Hmm.
it would be illegal to go after the nest in Germany. At least generally. There are of course exceptions, but you’d need to get the authorities involved and a specialist remove them.
you’d often need to dig, because the most annoying wasps (common wasp and German yellowjacket) often have their nests underground