Slap your UI team.
UI is oriented for tablets. It's ugly and unusable by normal people with laptops. Why would you leave so much empty space!? At least give user an option to get rid of your ridiculous padding.
column with chat members - why the .... I have to click several buttons and duck my brain to find the list? make a custom option for the user to include it as part of UI. I want to see who is in chat! not waste my time searching for how to do this.
sub-messages in chat? really? do you know the difference between chat and forum? at least make the location of the message in history VISIBLE, add a timeline that can be easily tracked.
Custom privacy in Team rooms. Why all users assigned to one team got identical privacy rules on all sub-chats. If you work on cross-team contribution, you have to create another team every ducking time! what a poor decision! what disorganised mind proposed that? seriously... gosh...
I know you will delete this. Cowards who freakout to face criticism. And I HAVE TO use this piece of... So the only option I've got is to comment into ducking suggestion box. Thank you Microsoft! I'd change my opinion if you'd accept the feedback and give user a choice.