I think we should just remember when the default was changed and do not reset it if the platform remains unchanged after a restart.
For the use-case where someone deploys an image to others and wants to make the "best guess default", I think that would work.
However, I'm wondering whether this auto-selection behavior should be tied to the platform or the user. It could be the user wants the Command-key look-and-feel to remain the same, regardless of platform. This could occur for users wh bring their image back and forth between different platforms, or a writer who deploys an image-based application to others with explicitly mapped keys that should not change, regardless of platform.
Maybe we underestimated #automaticPlatformSettings. Maybe it was trying to rightly separate those two issues. What do you think?