do the ORG filtering as part of the mongo query. Also, don't trigger metadata inheritence calculations when just trying to load 'about' information, which is not tied into the course tree anyhow (i.e. no parent/child relationship)

lms/djangoapps/branding/__init__.py

@@ -10,7 +10,10 @@ def get_visible_courses():
     """
     Return the set of CourseDescriptors that should be visible in this branded instance
     """
-    _courses = modulestore().get_courses()
+
+    filtered_by_org = microsite.get_value('course_org_filter')
+
+    _courses = modulestore().get_courses(org=filtered_by_org)
 
     courses = [c for c in _courses
                if isinstance(c, CourseDescriptor)]
@@ -25,8 +28,6 @@ def get_visible_courses():
     if hasattr(settings, 'COURSE_LISTINGS') and subdomain in settings.COURSE_LISTINGS and not settings.DEBUG:
         filtered_visible_ids = frozenset([SlashSeparatedCourseKey.from_deprecated_string(c) for c in settings.COURSE_LISTINGS[subdomain]])
 
-    filtered_by_org = microsite.get_value('course_org_filter')
-
     if filtered_by_org:
         return [course for course in courses if course.location.org == filtered_by_org]
     if filtered_visible_ids: