In stream option it would be a list element with options to add new items to this list.

List name : Slow Chat Based On Viewers [+]

Would allow the option for larger streams to increase the duration of slow chat based on a threshold of viewers. The more people that join the longer the slow chat duration. This would assist with automatic chat control, and allow streamers the peace of mind that when they stream later and viewer count goes down that the restrictions placed on chat would automatically get lifted. Option to add threshold would also be ideal. Threshold would mean the minimum +/- viewers for the new time to be enforced. So if you had 200 viewers and you wanted it to be enacted with a threshold of 15 that means at 215 viewers the slow chat mode would change. Then, at 185 viewers it would go down to the previous tier of time. This will allow for a flux of viewership and would remove the issue of hitting 200 and going to 15 slow, then hitting 299 and going back to 10 slow, and repeating that over and over and over as viewership fluxuates.

For instance:

[Viewers] 200 [Seconds] 5 [Threshold] 15(Activates at 215 - goes back to no slow at 185)
[Viewers] 300 [Seconds] 10 [Threshold] 15 (Activates at 315 - goes back to 10 second slow at 285)
[Viewers] 500 [Seconds] 15 [Threshold] 10 - (Activates at 510 - goes back to 10 second slow at 490)