We run a large number of Moodle instances and frequently find that performance suffers when courses become very large. This is often because teachers can only combine grades from a single course. In some cases, we’ve even had courses with over 200 activities that took more than two minutes to load.
That is why I would suggest building a tool that can combine grades from different courses and calculate a final year mark. This should allow teachers to compile grades from all their courses. This would make it easier to reuse courses and improve performance.

(AI-generated)
What ideas do you have for such a tool? Is there any interest in this?
Why subcourses does not help as a plugin?
The subkurse plugin can only import one mark from a sub-course. However, teachers usually need an overview of all marks awarded.