Is there a way of exporting a Reality Composer scene to a .usdz, rather than a .reality or .rcproject? If not, what are your suggested ways of leveraging Reality Composer for building animations but sharing to other devices/platforms so they can see those animations baked into the 3D model?
Yes, on macOS, you can open [from the menu bar] Reality Composer ▸ Settings [or Prefences on older versions of macOS] and check Enable USDZ export