Marc This is mostly so any paper mail can be sent to my home address in the US instead of to an address that I will no longer be residing at.
Be aware that as soon as you're no longer a resident of the Netherlands or another EEA country (regardless of your nationality), you're not allowed to have a bunq account any longer. It's not just because of paper mail, that's an actual requirement. Of course you're free to risk not abiding by bunq's current Terms of Service, but I would advice against doing that.
I do completely agree with your idea, though. It would be nice if more countries would be supported. Even if we only still have Euro accounts.