Pretty much as it says in the title. Interrupting live content is the most patently stupid way of going about this. I suggest the following:
1. Make the forced mid rolls use the smaller picture-by-picture player and make them silent so the stream doesn't need to be muted.
2. Use banner ads instead.
3. Pause the live stream in the background while the ad plays so that viewers don't miss anything.
4. Abandon the idea altogether.
5. Give creators full control of when they play and what ads get played.