Preferences: Adding Categories in External Tools of Environment is Clunky

When going to Edit->Preferences->Environment->Add->Add Category, you cannot remove added categories manually even if they are empty. You have to leave them empty and close/reopen preferences to get the added categories to go away. I would recommend adding the ability to manually remove custom added categories, and delete all of their associated tools. Or at least be able to remove the category after all tools have been removed.