It would be great if you could hold down Control and select multiple people to start a conversation with them without creating a new private team, similar to the way you can do it on Skype.
For this, of course, you would need a more convenient list of people to choose from.
(Perhaps the Search on the top-left should be extended to include sub-categories, e.g. searching for messages or searching for people, although I would also want it to work from the list of direct chats I have at present; i.e. I would like to select people from there).
Customer support service by UserEcho