Progressive Scan Chat (Chat Order of Appearance)
Current Chat is hard to read in streams with lots of viewers. Chats scroll up as new chats appear making it hard to for the eye to track at high speeds.
I'd suggest creating a mode where chat can use a "progressive scan" approach much like old CRT televisions which illuminated pixels sequentially overwriting old pixels. With this approach, new chats would overwrite the oldest chat. The next chat would overwrite the next oldest chat. Chats would stay in a fixed position on the screen until they were overwritten by a new chat. This would make it easier to read since chats wouldn't be moving.
Image example: https://en.wikipedia.org/wiki/File:CRT_image_creation_animation.gif