Server-wide categories for your sidebar
The new feature "costume category" gives the option to re-sort your channels and also Direct Messages.
It would be great if that would work Server-wide and not only Team-wide.
Exspecially for Direct Messages it would help to be able to sort them. It could work like the "Favorite" which is also server-wide.
It could also be an option to have it server-wide optional by a setting