Hi - I am Hosted and my host did create a "my courses" drop down above the Bread Crumb Trail that omits courses from Specific category IDs - which works great.
But I do have a few informational courses "Guidance Course, Senior Course, Tech Support Course" etc... that are set to not show grade books -- these are the courses I'd love to be able to omit from the Nav block and the Dashboard Course Overview block (though I understand the reason both display all courses a users is enrolled in so they can find all their enrolled courses from anywhere).