Hi, thank you for your input. Unfurtunately, this cannot be solved. 1) I cannot assign "Frankfurter Straße 79" to this building, as addresses have to be unique. 2) If I assign "Frankfurter Straße 79" to the whole area/premise, nominatim wouldn't know which building is the main "Frankfurter Straße 79". I could add a "main entrence" but -as far as i know- Nominatim would ignore that.
I keep it as it is and close the note. I also think that this should not cause any problems in real life.
If this does cause real-life problems, please feel free to open another note (preferably as a logged in user) and we can see, how we can help you.
Bye 