Some things to fix in the chat: 

ACP: Allow to filter chat logs by public, private and both like in 3.x

Private chats: When a user private chats another on mobile they have to post a dot or character to scroll and see the reply. this doesn't happen however in public chat. 

Some things I'd like to see in Chat:

A chat widget that appears as an Image Chat button and it floats in a specified position.  It  should scroll up and down the page with the page.

To have a chat session that happens on the same webpage throughout your website instead of a separate browser window.

 

A chat update is still planned.