You appear to be saying that even though some of the per system defaults you want are present, they are not automatically used, but users must go into the options dialog to select bindings other than Windows. Correct? And you would like to change this?

The odd situation we have is that default configuration in idlelib is specific to the installation, but the same for all users, whereas user overrides are specific to the user, but the same for all installations. Thanks for the reminder that we need to be careful. I will consider this before we change the location of format width in #20579.  As I say there, some changes will need Idle What's New entries and perhaps a reminder to read it in the signon message, and access from the help menu.