xfa.host.name will always give you the name of the XFA renderer (e.g. Acrobat, Reader),not the container (standalone, IE, Firefox). Therefore, your approach makes sense.
I believe this is because LiveCycle Designer follows the versioning of the LiveCycle suite, while AEM Designer follows the versioning of Adobe AEM (CQ).
You can keep the instructional pages intact, but you're going to need to add an extra (blank page) to the PDF in Acrobat before importing it into LiveCycle. You will open your PDF as a fixed layout design aka Foreground-XFA. Note the some features will be disabled when using this method.