DTB, What you say about currency conversion at IBKR is very useful as last year when transferring money from Germany to NZ the German "comdirect" bank's rate EUR->NZD was an outrageous good 2% worse than the official EZB rate (banking Ombudsman just discarded my complaint) --- same as 3 years ago when the conversion took place at NZ's ANZ bank which also overcharged 2% (but immediately caved in and corrected that after complaining at the ombudsman).

So in the future when transferring money between Germany and NZ I will only use Transfer Wise --- and it's good to know that with IBKR that won't be needed with my US account.

But most important of course is the knowledge to be able to have another US broker should I indeed move to NZ. I think I open an account now, as I already was thinking of splitting for safety reasons my Schwab account between two brokers.

Problem solved (though I now really wonder why NZ for Schwab is a "impermissible country").

DTB, very helpful. Thanks a lot!