The easiest method of applying OSConfig to a New PC is directly from a Package and a Run Command Line. This method is not recommended for testing as the OSConfig progress is not displayed.
The following steps are required
OSConfig must be created as a Package (no Program)
Create an ConfigMgr Package
Create a new Package with Source Files to the root of your OSConfig content. Do not create a Program. Distribute Content to your Distribution Points
Task Sequence Run Command Line
Add a Run Command Line step after the "Setup Windows and Configuration Manager" step. Use the following Command Line: