Hi @carson.zoom,
I’ve updated to the latest SDK v5 released tonight (https://github.com/zoom/zoom-sdk-macos/releases/tag/v5.0.24433.0616), and unfortunately I reproduced my application hang with custom video on this release as well. Using the latest macOS demo application bundled with the v5.0.24433.0616 SDK I was able to reproduce the application deadlock on the demo app pretty easily when custom UI is enabled, using the same procedure as described in my initial post on this topic. So it appears this issue has not been fixed with the latest SDK release 
You mentioned in your first reply on this topic that this issue should not affect SDK integration with our app and that there was an issue with the demo app itself. Could you please elaborate? The impact of this issue is significant enough that we’re looking for help on any kind of workaround/fix in the immediate term.
Thanks,
Nitin