Reports : Sorting on Calculated columns

Originally posted in github :
https://github.com/mautic/mautic/issues/3971

Mautic 2.8.0 introduced the possibility to group by and add Calculated columns
But there’s no way to sort the data using this Calculated columns

My scenario is : group all contacts per country, count contact ID, and SUM the points
Order by numbers of contacts DESC, and then by number of points DESC.

No way to achieve that as the Calculated columns are not listed within the “order” part