I didn't know that "Alt+Cmd+<something>" is necessary to enable "Alt+N" on some Mac computers. Definitely, Alt+N works perfectly on our Macintosh machines.
I'm sorry for this problem, but please realize that we cannot have all existing Apple computers at hand for testing. We have a 2008' Mac Pro and now also an iMac since the beginning of March. We don't have a Mac laptop, and this won't change in the foreseeable future. PI does nothing 'special' with the keyboard (nothing I'm aware of, at least), so I don't know why this happens.
Is this "Alt+Cmd+N" problem laptop-specific? Can you confirm this?