I’m just up to the Chapter 8 Animation section of the book, but the starter project will not run for macOS (11 beta 9), giving errors that seem based in C++ libraries around reading the USDA / USDZ files.
For macOS it complains that there are errors with unregistered VtValue types and verification failures. I am able to open the file in RealityConverter (beta 3) and see the ball in it, and it loads in the iOS simulator (after renaming the file to itself…?). In Xcode it won’t preview it as a USDA or converted to a USDZ.
See this pastebin here for the full error message.