Add scroll back length adjustable in settings.
Being able to increase the max scroll back value beyond the 150 limit would help a lot with chat moderating, and help with chat interaction from the broadcaster. This feature would disabled by default in settings but once enabled the user will be able to set the value to his/her liking. Having a maximum limit to start with ex. 10K would be a great start, with the set maximum value becoming bigger over time.
Also, if you could view the last streams/chat reply in one full log , with mod actions, that would be soo.. sooo.. pleased by a lot of mods I bet..
Edit, 1K scroll back length for the maximum would be a better place to start, then gradually increasing the maximum over time.