Hi Barry,
The guide doesn't do anything to the default user profile besides copy over the profile of Administrator. So I'm wondering what could cause the issue that you're seeing.
Which version of Windows are you using?
If you're not going to use the Mandatory Profile, you need to apply OSOT to the default profile and there is no point in doing the sysprep/copyprofile. I'm not sure if using Persona is a wise idea, I'd highly recommend using UEM with folder redirection.