We use the "mandatory" flag to designate requirements and to separate compliance courses from electives. Most of the time, mandatory courses are the only ones with due dates, so it's likely that the manager can just use "overdue" to see if their team is compliant or not, but I know they'll want to include or exclude this category of courses when they drill into some of the tiles.
This makes a lot of sense and should be a tile.
I agree. We have a lot of required courses for new-hire onboarding and some optional but it confuses managers as they don't know what is required.