Course order on Discover New page

My organization wants the courses on the Discover New page to be sorted by the course number, rather than by the standard options (start date or announcement). Previously, I had modified /edx/app/edxapp/edx-platform/common/djangoapps/student/views/management.py and /edx/app/edxapp/edx-platform/lms/djangoapps/courseware/views/views.py to use a function I added to /edx/app/edxapp/edx-platform/lms/djangoapps/courseware/courses.py:

def sort_by_display_number(courses):
    """
    Sorts a list of courses by their display number (e.g., AI100, GD300)
    """
   
    key = lambda course: course.display_number_with_default
    courses = sorted(courses, key=key)
   
    return courses

We recently enabled course discovery, and now the courses on the Discover New page are ordered by their start date again. I assume that’s because course discovery is populating the Discover New page with the results of a query with no search terms.

I have looked around, and I’m wondering if the course_run_sort function in /edx/app/discovery/discovery/course_discovery/apps/course_metadata/models.py controls the sort order returned by course discovery for the Discover New page.

I have two questions:
1- Am I correct that the course_run_sort function is what controls the sort order returned by course discovery on the Discover New page? And if not, what does control the sort order?

2- If so, it seems like I could modify that function to return self.number instead of course_run.start/course_run.enrollment_start. I’m a bit worried though because the comments on number in the Course class say “TODO Remove this field.”

Thank you!
Rebecca