I do understand that Twitch needs the ads that run during the streams for revenue but I find the unpredictable timing of the ads to be very problematic.

I very much wish that I could schedule the ads to run at a regular time. My preference would be at a predetermined number of minutes before the bottom of the hour. If I knew that they were coming every hour at that time then I could plan accordingly. (I so dislike the pre-roll ads as I think they quite often discourage potential viewers from watching my stream and will do whatever I can to avoid the pre-rolls i.e. running regularly scheduled ads.)