Mac Studio M1 Max lag when editing multicam

So my situation was slightly different but I saw a lot of posts about people struggling with Multicam in PP on M1 Macs, so figured I'd post my solution here.

I have a maxed out M1 Ultra, 128 GB RAM using PP v23.6 on Ventura. 

I was experiencing significant lag with MC clips basically every time I did anything, a cut, a move, a trim– anything– I would get the spinning wheel for 3-6 seconds, which was frustrating to say the least. Nobody can work like that. I trashed my prefs and installed previous versions, but nothing worked. 

Finally, through trial and error, I realized it was the MC audio causing the problem. I option + selected all the MC audio (so the MC video was unselected) and flatenned it (right click > Multi-Camera > Flatten). That was it, that was the solution. It hated the MC audio. 

This may not be the most ideal solution, but if you're on deadline and you gotta fly, try this and see if it works. I spent 5 minutes re-linking all the intact MC video clips to the newly flatenned audio clips and I'm back in action. 

Good luck, hope this helps someone.

I have similar issues happening on M2 Max with the PP23.3. For me, it seemed like when I would lay in a mogrt graphic that the timeline would stop updating the video playback. The audio would play, but the playhead would not move and the video would stay on single frame. Even if I moved the playehead, it would still stay on the same frame. After a day of headaches, restarting Premiere, I just went back to the previous version and that has no issues.