How can we improve WHMCS?

The customer's boxes should be in order organized by the administrator and drag drop would be the solution and nothing else in ASC order.

When publishing a file everything is out of order and impossible to change the boxes according to taste.

They can be organised by changing their default order values with hooks: https://docs.whmcs.com/Working_With_Client_Area_Home_Page_Panels#Default_Panels

However a UI to manage the appearance would make the process quicker and easier for us.