And i thought it was only me. have the same issue, i have a pretty good spec as well, mbp i5 16GB RAM + Razr Core X eGPU with Radeon 5700 XT video card. The livestream setup is getting hosts/participants in zoom on a separate computer in the local network, use NDI to grab the zoom screen to mimolive and send it back via NDI again so zoom viewers can see the mimolive stream, at the same time streaming it to facebook live. There is no issue when it’s using that way, issue comes up when it’s time to playback a video file, which have the generic export 720p setting/preset in premiere, the video stutters during livestream.
The fix i found is that i have to turn off the NDI upstream to the computer in the network that was running zoom, and only stream on facebook live. Problem now is that people in zoom cannot see the livestream and suggest to watch the stream on facebook but another problem is that there is a delay in facebook live. I just have to turn on the NDI upstream again to zoom once the video play back is finished.
So my guess is NDI scan converter which makes your screen an NDI source, and upstreaming it to a local computer in the network causes a 30-40% processing power. you can see this in your mac’s activity monitor. turning it off frees up extra processing resource. but it could be a different issue in your case. check activity monitor all the time and see what’s eating CPU usage while doing your livestream.