Yes, I also noticed that the shell is hanging in macOS Big Sur Beta 1 and 2. In macOS Big Sur Beta 2, I was able to resolve this issue by switching from my MacPorts back to the Apple's version of Zsh by doing the following: 1) In Terminal app, changed preferences for Shells Open with to the following: /bin/zsh Note: The above didn't work for me using macOS Big Sur Beta 1. 2) In the command line, performed the following for consistency: chsh -s /bin/zsh Well, I wish that this helps both you as well as others get past this issue.

After a bit of research, it appears that one can run via the iOS simulator but one will receive errors when trying to run via My Mac or Xcode Previews.

If you have enough available storage on your system disk, you can set up dual booting to take macOS Sequoia for a spin. Here's a very good reference video: https://www.youtube.com/watch?v=xzUPFeat9U4 Otherwise, one can use an external SSD or flash drive. Just remember to perform a TimeMachine backup before attempting any of these solutions.