I commend them for that. I don't remember an official visit but if one did take place it could've been before I was hip to this family. I do remember reading about members of the family doing something at Princeton. Can't recall what at the moment but that is in the area. I forgot about Constantin and Marie being in New York.
Most Americans wouldn't recognize anyone outside of the BRF and not many of them to be totally honest. If the
fürst walked through JFK airport, entourage in tow, he would probably be pegged for a wealthly businessman. (Something tells me he travels via private plane.

) If I were in those shoes I would probably want it the same way; anonymity at its best.
Love the avatar!