Our users have many different uses of grids, using multiple row groups and sorts. It's been a long time want of our users to sort row groups in certain ways but unfortunately have been unable to do this successfully.
A specific scenario, using ag-grid's demo olympic dataset: There is a table of athletes, grouped by date, then grouped by country. We want to sort the country groups rows by total number of gold medals descending, sort the date group rows by their own date descending and finally sort the athlete (leaf) rows by total number of medals.