Looking over this forum, I was hoping it would be you who’d respond!
I’ve been testing Litchi because streaming from the Fly DJI app to Twitch seems to suddenly have become unreliable. In early February it seemed to work OK and I streamed to it for 3-4 hours, but something has changed. Might be on my end, but I think its more likely an update to the DJI Fly app or the Mini 2 drone firmware.
One issue is that the DJI Fly app can have way too high a bitrate – like 20000kbps at my house over wifi. Twitch doesn’t want to see anything over 6000. At 20000 I can record the video on to Twitch, but it won’t stream it to viewers.
Litchi seems to cap its bitrate at 5500. But it doesn’t work either, although I get a buffering spinner instead of just a black screen – I think you may be correct on this being a keyframe issue.