So I understand that running 1:30 worth of ads will get you 30 mins of no pre-rolls and I think this is a great idea. However, 30 mins is a very short period of time to be able to go without interruptions. Even all the educational research shows that a 50 to 10 ratio is what works best for presentations.

1:30 giving you 30 mins of no pre-roll is great, but 3:00 should give you 1 hour that way the streamer can plan their content around the 50 mins of presentation, 10 min break with 3 of that being ads.