As I explained already in my threads, navigation of 2.x is very complex and deeply nested into the core logic, as far as I see and if I didn't miss anything. So adding any features I have implemented in my own blocks is not easy for me. It might be better and faster to ask them directly to the core programmer(s) of the navigation module.
There is also an old problem, when students do not get unenrolled by the teachers, which makes the myCourses list grow longer and longer with each semester. I know, this is only a problem for universities like ours, where the students are enrolled in many courses a semester and continue from semester to semester and teachers forgetting to unenrol them or leaving them in so that they can come back to the course during the whole cycle of 3 or 4 years.
That's why the next feature scheduled for both my blocks is a simple GUI switch to display actual courses and all courses. The only question at the moment is how to define what is recent or actual and what is older. The criteria range from courses the users actually attends to courses the user did not visit in the last 6 months or 12 months. This would keep development work and effort very low whereas developing a GUI where the user can select every single course with checkboxes to display/hide, would mean a lot of work because I would have to track every choice for every user in the database. So to be clean and lean a time based criterion already tracked in the database would make it easier. Time stamps are to be found in the mdl_logs table and maybe in other ones. I have to research this first.
As soon as this is clear for me, I will implement it.
And if such an option to let the students decide themselves what has to be displayed in their myCourses list is not present in Moodle 2.x this would be a further reason to rewrite my navigation block or to ask for it to the core developers.