As a streamer myself I understand that people like their own Twitch page to be theirs to control. A lot of people disable ads on their own channel and a lot will also run them willingly while streaming. Try giving more options we can opt into on our own channels. Without blocking our content at the same time, unless we choose to do so. Here's an idea or so:

• Brb ads
  (We already have, and do get used. Nice example to start)

• Lower thirds
  (Could allow us to set them to pop up as often as we like. Minimum of every X minutes that you (Twitch) can make a pre requisite for signing up.)

• Chatbox ads
  (For me personally, my average chatbox can show roughly 20 messages. Will be different for everyone with resolutions and zoom. We don't NEED to see those messages all the time. We've already read the ones at the top. Add an option where occasionally the top half of the box contains an ad.)

• Ads for channel points
  (I understand that the bit ads actually cost you too. With bits being a real currency. However, channel points are just data. Totally free on your end (I assume). Why not offer people an option to boost channel points with an ad? In fact I'll take this one slightly further. EVERYONE loves emotes. We all strive to unlock as many as we can! If we could make community pools where the viewers work together to hit a goal that could unlock emote slots! This way it costs nobody anything. And we all win. Granted, there are viewers who already have a ton of channel points. This may ruin it. If that's a big issue then make a second set of points. Name them ad points and only allow those to be used.)

• Panel Ads
  (We all have panels below our streams, and yes they don't get seen all too often. But they are there. use them, offer us to have an ad space down there with our other tabs. These are probably my weakest idea but it's worth a shot.)

• Ad timer
  (If you do keep the mid-roll ads, stick a timer on screen a minute in advance. Inform us "Ad running in 0:59", This allows us to prepare for it an advance. Pause our games, move to a intermission screen, whatever it may be. At least this way they don't pop out of nowhere and people miss you getting the final blow on the hard mode boss you've been grinding for over 3 days)

Hope even just 1 of these ideas helps somehow. Good luck!