That’s fair, if a mapper thinks that the common-sense, language-neutral name of a POI needs to combine each language’s name in a non-obvious manner, then I think they should be able to put that combination in name, cognizant of the tradeoff that speakers of German or Italian would see some duplication (a minor annoyance at most).
But if we allow for this kind of combination, then it needs to be possible to distinguish it from the POI next door that has a less sophisticated concatenation of the two languages’ names. Otherwise, the Italian speaker would now see “Bolzano (Carabinieri Bozen)”.
It’s only possible to combine the names in this manner because German and Italian share certain similarities, such as how they’d write “carabinieri”. Similarly, I’m reminded of a supermarket I used to shop at, named “Senter Market” in English and “Chợ Senter” in Vietnamese. To save space, the sign out front said “Chợ Senter Market”. (I always got a kick out of hearing the Garmin GPS say, “Arriving at Choh Senter Market.”)
But we can’t necessarily encode those combinations in name even if signposted. In the Houston seafood buffet example earlier, the sign spliced Chinese characters between each English and Vietnamese word. Even if that’s how the sign is laid out, seeing it written that way in any other medium looks like garbled text. I think there’s a limit to how faithfully we reproduce signs, because we aren’t in the signmaking business.