For the live chat in blind runs: Reserve the chat only for the streamer and bot.
I see many live streamers in a blind run who keep running the warning messages about hints, suggestions and spoilers and while I'm looking at all of it I keep thinking "why enable the live chat at all in this case"? "Why stream live at all when the option does not exist"?
The only way I could imagine it's possible is making the bot spam the clear command on chat continuously, but it would clear all the messages of the bot too that the others could find useful.
Other streaming sites have this option, so why not Twitch?