Thank you Alex for the ideas and confirmation I'm not crazy.
I am suspicious it's the PE version not causing the mount, but as long as it's reliable I can create the steps accordingly.I try and avoid unnecessary steps whenever possible.
I'm curious, how often have you run into the need for the fixwindows.exe? I've done imaging for a few years with various SCCM and WDS setups and never really ran into a situation where I've seen those kinds of problems. I'm wondering if I should add it to the template.