Sort legend in other way (for example by main category)

It looks like the legend is sorted by name, regardless if the item is a category or subcategory. But for a great visual effect it could be very useful to sort by main category, including at first all the subcategories

For instance I have the following:

"Meetings" category -> No parent
"All class reps" subcategory -> parent -> Meetings
"Parent Workshops" subcategory -> parent -> Meetings
"Parents Conference" subcategory -> parent -> Meetings
....
and other categories

Now this is how the legend is sorted:

"All class reps" "Events" "Exams" "Holidays" "Meetings" "Parents Workshop" "Parents Conference" "School Closure" "Summer Camp" "Term Dates" "Trips"

As you can see the items belonging to “Meetings” parent category are scattered in the list because sort occurs by category name…

Is there a way to achieve other ways to sort legend items?

https://wordpress.org/plugins/the-events-calendar-category-colors/